Comment of the use of dichloromethyl methyl ether as formylating agent .
5 Pages
English
Downloading requires you to have access to the YouScribe library
Learn all about the services we offer

Comment of the use of dichloromethyl methyl ether as formylating agent .

-

Downloading requires you to have access to the YouScribe library
Learn all about the services we offer
5 Pages
English

Description

ISSN 0009 - 2940 CHEMISCHE CHBEAM 121 1988 (1) 1 -194 BERICHTE A1 -AXVI Inhalt Contents Anorganische Chemie/Inorganic Chemistry du Mont, W.-W., Lange, L., l Eigenschaften von Tellur-Tellur-Bindun­ Properties of Tcllurium-Tcllurium Bonds. Karsch, H. H., Peters, K., Peters, E.-M., gen, VI. — Struktur und Barriere der VI. — Structurc and Barrier of Intercon-von Schnerins, H. G. Enantiomerenumvvandlung von Bis(2.4.6- version of Enantiomeric Conformations of tri-/iT?-butylphenyl)ditellan Bis(2A6-tri-/tr/-butylphenyl)ditellanc Hetterich, W., Kisch, H. 15 • Heterogene Photokatalysc. V. - Cad- Heterogeneous Photocatalysis. V. — Cad-mium-Zinksulfidc als Katalysatoren der mium-Zinc Sulfides as Catalysts for the Photodehydrodimerisierung von 2.5-Di- Photodchydrodimerization of 2,5-Dihy-hydrofuran drofuran Bogdanovic, B., Schlichte. K., 27 • Dehalogenierungcn von geminalcn Di- Dehalogcnation of Geminal Dihalocyclo-Westeppe, U. halogencyclopropancn, xa-Dichlorcyclo- propanes, xa-Dichlorocyclobutanones, butanonen und Halogcnketoncn mit Hilfe and Halokctoncs by Mcans of Magnesium Anthraccnc • 3 THF von Magnesiumanlhraccn • 3 THF 33 • Neue Magncsiumanthraccn-Komplcxe New Magnesium Anthracene Complcxes Bogdanovic. B., Janke, N., Kinzclmann, H.-G., Westeppe, U. durch Ligandenaustausch by Ligand Exchange Paetzold, R, Pelzer, C, Boese, R. 51 • Die Addition von Lithiumalkaniden an The Addition of Lithium Alkanides to Im-Iminoborane inoborancs Formation, Structure, and ...

Subjects

Informations

Published by
Reads 81
Language English

Exrait

ISSN 0009 - 2940
CHEMISCHE
CHBEAM 121
1988 (1) 1 -194 BERICHTE
A1 -AXVI
Inhalt Contents
Anorganische Chemie/Inorganic Chemistry
du Mont, W.-W., Lange, L., l Eigenschaften von Tellur-Tellur-Bindun­ Properties of Tcllurium-Tcllurium Bonds.
Karsch, H. H., Peters, K., Peters, E.-M., gen, VI. — Struktur und Barriere der VI. — Structurc and Barrier of Intercon-
von Schnerins, H. G. Enantiomerenumvvandlung von Bis(2.4.6- version of Enantiomeric Conformations of
tri-/iT?-butylphenyl)ditellan Bis(2A6-tri-/tr/-butylphenyl)ditellanc
Hetterich, W., Kisch, H. 15 • Heterogene Photokatalysc. V. - Cad- Heterogeneous Photocatalysis. V. — Cad-
mium-Zinksulfidc als Katalysatoren der mium-Zinc Sulfides as Catalysts for the
Photodehydrodimerisierung von 2.5-Di- Photodchydrodimerization of 2,5-Dihy-
hydrofuran drofuran
Bogdanovic, B., Schlichte. K., 27 • Dehalogenierungcn von geminalcn Di- Dehalogcnation of Geminal Dihalocyclo-
Westeppe, U. halogencyclopropancn, xa-Dichlorcyclo- propanes, xa-Dichlorocyclobutanones,
butanonen und Halogcnketoncn mit Hilfe and Halokctoncs by Mcans of Magnesium
Anthraccnc • 3 THF von Magnesiumanlhraccn • 3 THF
33 • Neue Magncsiumanthraccn-Komplcxe New Magnesium Anthracene Complcxes Bogdanovic. B., Janke, N.,
Kinzclmann, H.-G., Westeppe, U. durch Ligandenaustausch by Ligand Exchange
Paetzold, R, Pelzer, C, Boese, R. 51 • Die Addition von Lithiumalkaniden an The Addition of Lithium Alkanides to Im-
Iminoborane inoborancs
Formation, Structure, and Reactions of Paetzold, R, Eleftheriadis, E., 61 • Bildung, Struktur und Reaktionen von
Minkwitz. R., Wölfcl, V., Gleiter, R.. Mcthyl(mcthylimino)boran Mcthyl(methylimino)borane
Bischof, R, Friedrich, G.
Schwab, M., Sundermeyer. W. 75 • Bis(trifluormcthyl)sulfin. (CF,):C = SO: Bis(trifluoromethyl)sulfinc, (CF,)2C = SO:
Additionsreaktionen mit Thiolcn, Amin- Addition Reactions with Thiols, Amine yV-
N-oxiden, Ethern und 1,3-Dipolcn Oxides. Ethers, and 1,3-Dipoles
Kuhn, N., Schumann, H., III • Synthese und Reaktivität von Dienyl- Synthesis and Reactivity of Dienylmetal
Winter, M., Zauder, E., metall-Verbindungcn, XXIX. — Protonie- Compounds, XXIX. — Protonation of
rung von CsHsFcC6H7 zu Cyclohcxadien CsHsFeC^H- to Cyclohcxadicnc and Con-
und Folgereaktionen sequent Reactions
Evcrtz, K., Huttncr, G. 143 • Regio- und Slcrcoscicklivilät der Halogen­ Regio- and Stcreoselectivity of Halogen
substitution in Fc2(CO)6(u-PRCI)(ü-Hal) Substitution in Fc2(CO)6(u-PRCl)(u-Hal)
Ziegler, M. L., Blechschmitt, K., 159 • Darstellung und Charakterisierung von Synthesis and Characterization of (CTLh-
Nuber, B., Zahn, T. Tctrahedranen des Typs Cp:,M;,As(CO)(, M,(CO)f,As and (C5H5)2M2(CO)4As2 and
und Cp2M2As2(CO)4 (Cp = C5H>, M = Derivatives of the Arsanetriyl Tctrahed-
rane Mo, W) sowie von Derivaten dieser Tetra-
hedrane
Baudler, M., Becher, R., 173 • Beiträge zur Chemie des Phosphors, Contributions to the Chemistry of Phos-
Germeshauscn, J. 182. - Li2P26R2 und LiP26R, (R = Mc. phorus. 182. - Li2P26R2 and LiP26R3
Et) — die ersten teilmctallicrtcn Hcxa- (R = Me, Et) - the First Partially Me-
cosaphosphane(4) talatcd Hexacosaphosphancs(4)
Eischenbroich, C, Schneider, J., 177 • Mctall-7i-Komplexc von Benzolderivatcn. Metal 7t Complexes of Benzene Deriva­
Wünsch. M., Pierre. J.-L.. tives, XXX. - rf-, Mn6:n6K and ur XXX. - rf-, u2-(n6:if)- und ur
Baret, P., Chautcmps, P. (rf: i"|6: ii6)-[23]Paracyclophan-Koinplexc (r](>: rj6: ri<,)-[21]Paracyclophane Com­
des Chroms. Darstellung, kernmagne­ plexes of Chromium. Preparation, Nuclear
tische Resonanz und Rcdoxverhaltcn Mamietic Resonance. and Redox Behavior
Organische Chemie/Organic Chemistry
von Doering, W. E., Roth, W. R., • Verbotene Reaktionen. — [2 + 2]-Cyclo- Forbidden Reactions. — [2 + 2] Cyclo-
reversion of Risiid Cvclobutancs Breuckmann, R., Figge, L., reversion starrer Cvclobutane
Lennartz, H.-W., Fessner, W.-D..
Prinzbach, H.
Adam, W., Lupön, P. 21 Die Chinolepoxide des /j-Kresols und Quinol Epoxides from p-Cresol and Es­
Östrons mittels Photooxygenierung und trone by Photooxygenation and Ti-
Titan(IV)- oder Vanadium(V)-katalysier- tanium(IV)- or Vanadium(V)-Catalyzcd
tem Sauerstofftransfer Oxvgen Transfer
• Publikationssprachc • Langnagc of Publication
Fortsetzung: bitte umblättcrn/Continucd: please turn over Inhalt (Fortsetzung) Contents (Continued)
Bogdanovic, B.. Schlichte, K., 27 • Dehalogcnierungen von geminalen Di- Dchalogcnation of Geminal Dihalocyclo-
Westeppc, U. halogencyclopropanen, a.a-Dichlorcyclo- propanes, a,a-Dichlorocyclobutanones,
butanonen und Halogcnketonen mit Hilfe and Halokctoncs by Means of Magnesium
Anthracene • 3THF von Magnesiumanthracen -3THF
Hcuschmann. M. 39 • Mehrstufige inverse Diels-Alder-Rcak- Multi-Step Inverse Diels-Alder Reactions
tionen von 1.3-Dimethyl-2-mcthylcnimi- of 1,3-Dimcthyl-2-methylcneimidazolidine
dazolidin mit 2.4-Hexacliensäure-methyl- with Methyl 2,4-Hexadienoates
estern
D'Anello. M., Erba, E.. Gelmi. M. 1 67 5-Oxazolone. II. - 2,4-Diaryl-4-(2,4-dini- • 5-Oxazolones, II. - 2,4-Diaryl-4-(2,4-di-
Pocar. D. troaryl)-5(4/7)-oxazolone: Synthese und nitroaryl)-5(4f/)-oxazoloncs: Synthesis and
säurekatalysierte Umwandlung in 1-Hy- Acid-Catalyzcd Transformation into 1-
droxy-lH-indazol-Dcrivate Hydroxy-l/Y-indazole Derivatives
Kreher. R. P.. Hildebrand. T. 81 • Untersuchungen zur Chemie von Isoin- Studics on the Chemistry of Isoindoles and
dolen und Isoindolenincn. XXVII. — 2- Isoindolenines. XXVII. - 2-Alkyl-2//-di-
Alkyl-2//-dibenz[e.(/]isoindole: Synthese, benz[f,g]isoindoles; Synthesis, Properties,
Eigenschaften. Reaktionen Reactions
Buss. V.. Klein. M. 89 Berechnungen der elektronischen Struktur • Electronic Structurc Calculations of a
eines chiralen [2.2]Metacyclophans Chiral [2.2]Metacyclophanc
Gotthardt. H., Böhm, F.-R.. 95 • Pyrrolo[l,2-/)]-l,3,4-thiadiazol-Derivatc Pyrrolo[ 12-h]-1,3,4-thiadiazole Deriva­
Brauer, D. J., Weisshuhn. C. M.. aus mesomeren Hetcropentalenen und tives from Mesomeric Heteropentalenes
Wilke. C. J. Azodicarboncstern and Azodicarboxylic Esters
Liguori, A., Romeo. G.. 105 N.O-Hctcrocyclen, 24. - Eine neue Un­ • N,0-Heterocycles, 24. — Novel Approach
tersuchung der Ringöffnung von Isoxazo- to the Ring-Opening Reaction of Isoxa-Sindona. G.. Uccella. N.
lidiniumsalz.cn zu 1,3-AminoaIkoholen zolidinium Salts to 1.3-Amino Alcohols
• Raccmisierungsfreic Eisen(III)chlorid-ka- Ferric Chloride-Catalyzcd Acylation of
talysicrtc Acylierung von Aromaten mit N- Aromatic Compounds with A^-Phthaloyl-
Effenberger, R., Steegmüllcr. D. 117
Phthaloyl-a-aminosäurechloriden a-amino Acyl Chlorides without Racemi-
sation
• Intramolekulare Friedcl-Crafts-Acylie- Intramolccular Fricdel-Crafts Acylation of
Null, V.. Ziegler. T. rung von A;-Phthaloyl-substituierten Aryl- A'-Phthaloyl-Substituted Arylalanyl and
Effenberger, F., Steegmüllcr. D.. 125
und Homophcnylalanylchloriden Homophenylalanyl Chlorides
Quast. H., Christ, J., Klaubert. C. A.. 131 • Stereochcmic der Hydrocyanierung von Stereochemistry of the Hydrocyanation of
Peters, E.-M., Peters, K., 1,5-Dimethylbicyclo[3.3.0]octanonen und 1,5-Dimethylbicyclo[3.3.0]octanones and
von Schncring, H. G. -oetenonen -octenoncs
Eischenbroich, C. Schneider. .1., 1 77 • Metall-rr-Komplexe von Bcnzolderivaten, Metal TC Complcxcs of Bcnzenc Deriva­
Wünsch, M., Pierre. J.-L., Barct. P., XXX. - r\\ Mn^n")- und M.r(n6: tives, xxx. - ii6-, Mn6:n6K and u3-
Chautcmps. P. n/': r|(,)-[2,]Paracyclophan-Komplexc des (r|6: if1: r|f,)-[23]Paracyclophane Com-
Chroms. Darstellung, kernmagnetische plexes ofChromium. Preparation, Nuclear
Resonanz und Redoxvcrhalten Magnctic Resonance, and Redox Behavior
Ried, W.. Reiher, U. 185 • Dicls-Aldcr-Rcaktionen von 2,3-Bis(/<r/- Diels-Alder Reactions of 2,3-Bis(/erf-bu-
butyldimcthylsilyloxy)-l,3-butadien mit tyldimethy!silyloxy)-l,3-butadiene with
Heterodienophilcn Heterodienophilcs
Drewello. T., Fessner, W.-D.. 187 • Gasphasenoxidation („Charge-Stripping") Gas-Phase Oxidation ("Charge Strip­
Kos, A. J., Lcbrilla. C B., von ionisierten Pagodanen und verwand­ ping") of Pagodane Radical Cations and
Prinzbach. H., von Rague Schleyer, P.. ten Käfigkohlcnwasscrstoffcn. — Eine Related Cagc Hydrocarbons. — A Theo-
Schwarz. H. theoretisch-experimentelle Studie zu Te­ retical-Experimental Search into Tetra-
tramethylen-Dikationen methylenc Dications
von der Brüggen, LL Mayr. H. 191 Beitrag zur Verwendung von (Dichlorme- • Comment on the Use of Dichloromethyl
thyl)methylether als Formylierungsrea- Methyl Ether as Formylating Agent
genz
AI Richtlinien für Autoren • Instructions for Authors
• Publikationssprache • Languagc of Publication U. von der Brüggen.. H. Mayr 191
Comment on the Use of Dichloromethyl Methyl Ether as Formylating Agent
Uwe von der Brüggen and Herbert Mayr*
Institut für Chemie, Medizinische Universität zu Lübeck,
Ratzeburger Allee 160, D-2400 Lübeck 1, Federal Republic of Germany
Received August 2 7, 1987
methyl ether (1), though complications caused by anomeric stabili-
In contrast to no rmal alkenes, dialkylacetylenes can be formy- sation of 1 might be expected.
Iated with dichlo romethyl methyl ether (1) in the presence of 1.2 When Compound 1 was treated with one or two equivalents of
equivalents of boron trichloride. A rationalisation for the dif- isobutene in the presence of 1.2 equivalents of BC13, only the 2:1
ferent behaviour of alkenes and alkynes arises from the NMR
produet 4a was obtained, in aecord with previous reports2). Under
spectroscopic investigation of the reaction intermediates. similar conditions, 1 and tetramethylethylene (2c) selectively gave
the 1:1 produet 8 after hydrolysis. Steric strain obviously inhibits
the addition of 3c to a second alkene molecule.
Dichloromethyl methyl ether (1) has been used for the formyla-
tion of aromatic Compounds1', but attempts to formylate isobutene
Cl CH, CH,
H,C CH, 2a and trimethylethylene 2b gave only the 2:1 products 42>. It has
BCU I I 3 I 3
13 \ / * H,0
been concluded, therefore, that in electrophilic addition reactions 1 + HXO-C C C-Cl
c=c
3 I I I 90%
to olefins the chloro ethers 3 are more reactive than 12a).
H CH3 CH3 H,C/ XChU
2c 3c
Cl R CH,
9l R CH,
I I I 3 Cf-U CH,
0 I \ / * SnCL H.CO-C—C-C-Cl
HXO-C-Cl + C=C 5—>
3 III C-C C-Cl
H/ \H CH2C,2
H H CH3 '3 H / I H
CH3 CH3
R = H 2a
8 3a
R = CH3 2b
3b
R The termination of this addition aT the stage of the 1:1 adduet
I
3c allows to analysc the degree of ionisation of the reactants 1 and
+ 2/SnCl4 H3C0 /CH-C(CH3)2Cl
the 1:1 products 3. The NMR spectrum of a Solution of 1 and 1.2
C
equivalents of BC'l, in CD2C12 showed that 1 is not ionised under
H/ XCH-C(CH3)2Cl these conditions. When Compound 2c was added to this Solution,
the 'H-NMR spectrum showed singlets at 6 = 3.49 (OCH3) and R
at 5 = 5.87 (CH) as expected for unionised 3c. A fast exchange of
4a
Cl is indicated by the Observation that the diastereotopic methyl
4b
group Signals at ö = 0.94 and 1.01 and at 8 = 1.46 and 1.52 Analogously, the 1:1 products 6, inilially formed from 1 and
( —100°C) becamc equivalent when the sample was warmed up to ketene alkyltrimethylsilyl acetals 5, have been reportcd to react far
-20°C faster than the starting ether 13). Only when both R1 and R2 werc
Since 3a, 3b can be expected to ionise to a similar degree as 3c, alkyl groups, steric hindrance reduced the rate of formation of 2:1
products, and oc-tformylcarboxylic esters, hydrolysis products of 6, the exclusive formation of 2:1 products - if strong steric effects
are abseilt - can be explained on the basis of our general analysis: were isolable in addition to 7.
Compounds 3 form better stabilised carbenium ions than 1 and are
therefore more reactive in Systems with a small degree of
Cl R1 o ionisation4-5). In principle, it should be possible to obtain 1:1 pro­R1 OR3
ZnCL I I //
ducts by using stronger Lewis acids4). All attempts to formylate > H3C0-C—C-C
isobutene with 1 have failed until now, and 2:1 products in addition R2^ X0Si(CH3)
3>3 H R2 N°R3
to polymers were obtained when an excess of TiCl4, SnCl4, or AICI3
was employed.
R1\ /R2
+ 5/ZnCl2 H3CO Vc02R3
H
> C
HsCO^C R H C-CO,R3 H Si(CH3)3
+ 1
R1X V C=C ' U i TiClF
equimol. TiCl4
H H
10
We have demo>nstrated recently that the relative electrophilicity
of alkyl Chlorides depends on the degrec of ionisation. In pred-
ominantly unionitsed Systems the more readily ionised Compound
H2O ^C^
is found to be rmore reactive, while the opposite is truc when the
competing alkylaiting agents are ionised to a large extern4'. On this H H
basis, we have no>w analysed formylations with the dichloromethyl 11
Chem. Bcr. 121. 1191 -193 (1988) r VCH Vcrlagsgcscllschaft mbH, D-6940 Wcinhcim. 1988 0009-2940/88/0101 -0191 $ 02.50/0 U. von der Brüggen, H. Mayr 192
A different Situation arises, when the 1:1 producis give reso- Experimental
nance-stabilised carbenium ions. It has been reportcd that vinyl-
Generai: NMR: XL 200 (Varian), chemical shifts are recorded
silanes can be formylated by 1 in the presence of equimolar amounts
with respect to internal TMS. — Mass spectra: 70 — 250 (VG-In-
of TiCl46), while allylsilanes give only 2:1 products under these
struments). - IR: IR-435 (Shimadzu).
conditions6c).
We interpret this finding by the low intrinsic reactivity of the 3~Chloro-2,2,3-trimethylbutanal (8): A 1 M Solution of BC13 in
cations 10 which are initially formed from 1 and vinylsilanes. Since CH2C12 (36 ml) was added to a Solution of 1 (3.45 g, 30.0 mmol) in
similar types of 1:1 products may be formed by the addition of 1 30 ml of CH2C12 at -78°C. An of 2,3-dimethyl-2-butene
to CC triple bonds, we investigated the formylation of alkynes un­ (2c) (5.40 g, 64.2 mmol) in 60 ml of CH2C12 was added dropwise
der similar reaction conditions. within 30 min and allowed to react for 3 h at — 78°C. The mixture
When the dialkylacetylenes 12a,b were added to Solutions of 1 was washed with 100 ml of 25% aqueous NH4C1 Solution, the
and 1.2 equivalents of boron trichloride, the reactions terminate at aqueous layer extracted with two 20-ml portions of ether, and the
the 1:1 produet stage. Workup of the produet obtained from 2- combined organic layers were dried with CaCl2. Evaporation of the
butyne (1.2a) with methanol/potassium hydrogencarbonate gave a solvents gave 4.01 g (90%) of spectroscopically pure 8. — IR (neat):
mixture of 14a and 15a which was converted into pure 15a by 2974 cm"', 1720, 1458,1375, 1155, 1104, 829. - 'H NMR (CDC13):
treatment with methyl orthoformate. Hydrolysis of the formylation 8 = 1.21 (s, 6H, 2-CHj), 1.63 (s, 6H, 3-CH3), 9.83 (s, 1 H, 1-H). -
produet of 3-hexyne (12b) was carried out with aqueous ammonium 13C NMR (CDClj): 8 = 18.95 (q, 2-CH3), 28.90 (q, 3-CH3). 52.87
Chloride Solution to yield the stereoisomeric aldehydes (£.Z)-14b. (s, C-2), 73.68 (s, C-3), 204.41 (s, C-l). - 2,4-Dinitrophenylhydra-
zone of 8: M.p. 141 - 143°C (methanol). - MS (70 eV): m/z (%) =
330 (3), 328 (10) [M+], 252 (39), 251 (100).
R
C13H17C1N404 (328.8) Calcd. C 47.50 H 5.21 I
H,CO. .R
Found C 47.62 H 5.14
+ I/BCI3 3 x^©>cr o
Dichloromethyl Methyl Ether (1) and 2-Butyne (12a): A 1 M So­
R_C=C-R —I ® i BCl4°
lution of BC13 in CH2C12 (36 ml) was added to a Solution of 1 (3.45 g,
H CL
30.0 mmol) in 30 ml of CH2C12 at -78°C. Compound 12a (1.62 g,
R = CH3 12a 13a 30.0 mmol), dissolved in 60 ml of CH2C12, was added with stirring
R = C2H5 12bb within 1 h to give a slightly yellow Solution which became turbid
R R 30 min after completion of the addition. After 2 h, 25.0 g of K2C03
I I
and 10 ml of anhydrous methanol were added, and stirring at 0\ CR CR
(a) CH30H/K2C03 or \fj^ ^C^ (H,C0)9HC^ ^C^ — 78 °C was continued for another 15 min. The mixture was warmed
(b) NH4CI/H20 Hll at ambient temperature and washed with 30 ml of concentrated
14a 15a aqueous ammonia. The aqueous layer was extracted with two 20-
ml portions of ether, the combined organic layers were dried with
14b
Na2S04, and the solvent was evaporated to give a mixture of (E,Z)-
14a and (E,Z )-l5a. Complete acetalisation of 14a was achieved by
The ionic character of the intermediates 1.1 Wils proveil by 'II- stirring this mixture with methanol (0.96 g, 30.0 mmol), methyl
NMR spectroscopy. The spectrum taken aftcr addition of 2-butyne orthoformate (3.18 g, 30.0 mmol), and NH4N03 (0.2 g) for 14 h.
to a mixture of 1 and BC13 in CD2C12 showed methyl resonanecs After alkalisation with diisopropylamine, 30 ml of ether was added.
at 8 = 2.04, 2.80, and 4.97 and a broad one-prolon singlet at The mixture was filtered and distilled (64 —66°C/25 mbar) to give
8 = 9.67, as expected for 1-alkoxyallyl cations7'. Addi- 2.58 g (52%) of 15a (2:1 mixture of stereoisomers).
tional signals at 8 = 1.34, 2.24, and 2.30 (1:1:2) are close to those
(E,Z)-3-Chloro-l,l-dimethoxy-2-methyl-2-butene (15a): 'H NMR reported for the tetramethyleyclobutadiene aluminium chloride
(CDCI3), major isomer: 8 = 1.71 (mc, 3H, 2-CH3), 2.14 (mc, 3H, complex (1.32, 2.29, 2.40)8) and indicate that the BClj-initiated di-
4-H), 3.39 (s, 6H, OCH3), 5.27 (s, 1 H, 1-H); minor isomer: 8 = 1.80 merisation of 12a takes place as a side reaction. Lewis-acid-initiated
(mc, 3H, 2-CHj), 2.21 (mc, 3H, 4-H), 3.34 (s, 6H, OCH3), 4.93 (s, oligomerisations of alkynes become dominant with terminal and
1H, 1-H). - 13C NMR (CDCI3), major isomer: 8 = 12.19 (q, 2-aryl-substituted acetylenes, and attempts to formylate these types
CH3), 22.23 (q, C-4, possibly other isomer), 54.90 (q, OCH3), 103.91 of Compounds have not been successful.
(d, C-l), 128.76 (s, C-2), 130.96 (s, C-3); minor isomer: 8 = 14.01 (q,
Conclusion. Electrophilic formylations with dichloromethyl me­
2-CH3), 22.78 (q, C-4, possibly other isomer), 54.17 (q, OCH3), 102.8
thyl ether (1) have previously been achieved with aromatic Com­
(d, C-l), 128.1 (s, C-2), 129.7 (s, C-3). - MS (70 eV): m/z (%) =
pounds and vinylsilanes and now with dialkylacetylenes. Since all
166 (0.23), 164 (0.73) [M+], 135 (18), 133 (57), 129 (18), 97 (10), 75
these reactions require the use of at least 1 equivalent of strong
(58), 31 (100).
Lewis acids and lead to the formation of intermediate delocalised
C7H13C102 (164.6) Calcd. C 51.07 H 7.96
carbenium ions of low intrinsic reactivity, it appears that these two
Found C 51.67 H 7.81
conditions are needed for the use of 1 as formylating agent, in
aecordance with theoretical considerations4'. Until now, appro- Dichloromethyl Methyl Ether (1) and 3-Hexyne (12 b): A 1 M So­
priate conditions for the formylation of ordinary alkenes (very lution of BCI3 in CH2C12 (36 ml) was added to a precooled Solution
strong Lewis acids would be needed) have not yet been found, and (-78°C) of 1 (3.45 g, 30.0 mmol) in 30 ml of CH2C12. An
1 could only be used for the electrophilic formylation of alkenes, of 12b (2.46 g, 30.0 mmol) in 60 ml of CH2C12 was added within 30
when the electrophilic centre of the formylation produet was ste- min and stirred for 2 h at — 78'"'C. The mixture was poured onto
rically shielded. 200 ml of aqueous NH4C1 Solution (25%), the aqueous layer was
washed with two 30-ml portions of CH2C12, and the combined
organic layers were dried with CaCl2. Distillation at 65 — 80°C We thank Ms. Roswitha Lammers for experimental assistance and
(bath)/32 mbar gave 2.24 g (51%) of (E,Z)-3-chloro-2-ethyl-2-pen-the Deutsche Forschungsgemeinschaft for Financial support.
Chem. Ber. 121, 191 -193 (1988) Comment on the Use of Dichloromethyl Methyl Ether as Formylating Agent 193
tenal (14b) («2:1 mixture of stereoisomers) contaminatec! with 3H, CH,}, i.;:6 l ./ - 7.5 Hz, 3H, CH3), 2.70 (q, J = 7.5 Hz, 4H,
small amounts (sslO%) of an unknown impurity. - Mixture of 2CH:). 1 i..'4'h .. 1 H, NH), aryl H as usual. - 13C NMR(CDC13):
(£,Z)-14b: IR (neat): 1676 cm"1, 1609. - 'H NMR (CDCU): 5 = 12.41 (q), 13.47 q, 22.65 (t), 29.03 (t), 116.7 (d), 123.5 (d), 129.3 (s),
0.98 (t, / = 7,5 Hz, CH3), 1.26 and 1.29 (2 t, J = 7.4 Hz, CH3), 130.1 (d), 1 n.8 ,s) 138.2 (s), 144.5 (d), 144.8 (s), 146.1 (s).
2.34, 2.44, 2.64, 2.93 (4 q, J = 7.5 Hz, CH2), 10.01, 10.21 (2 s, ratio
2:1, CH = 0). - ,3C NMR (CDC13): 5 = 11.93, 11.98, 13.47 (3 q,
CH3), 19.47, 20.48 (2 t), 28.24, 30.59 (2 t), 139.40 (s, C-2), 154.82,
159.20 (2 s, C-3, assignment uncertain), 186.94,191.21 (2 d, CHO). -
" ,a) A. Rieche. H. Gross, E. Höft, Chem. Ber. 93 (1960) 88. -MS (70 eV): m/z (%) = 148 (32), 146 (100) [M 1 ], 133 (3), 131 (8),
lb' H. Gross. A. Rieche, G. Matthey, Chem. Ber. 96 (1963) 308.
119 (9), 117 (24), 111 (37), 95 (36), 93 (17), 89 (20), 81 (36), 67 (76).
2) 2al C. F. Garbers, H. S. C. Spies, H. E. Visagie, J. C. A. Boeyens,
When the crude reaction produet obtained from 30 mmol A. A. Chalmers. Tetrahedron Lett. (1978) 81. - 2b) C. Duschek,
B. Drews, M. Muehlstaedt Ger. (East) 115, 650 (Cl. C07 of 1 and 12 b was not distilled but treated with 2,4-
043/12) (12. Oct. 1975) [Chem. Abstr. 87 (1977) 5391 j].
dinitrophenylhydrazine9), a mixture of stereoisomeric 2,4-dinitro-
3) S. Tanimoto. T. Kokubo, T. Oida, H. Ikehira, Synthesis 1982,
phenylhydrazones (5.00 g, 51%) was obtained, which was separated
723.
by MPLC (30 x 2.5 cm LiChroprep Si 60. 15-25 u,
4) H. Mavr. C. Schade, M. Rubow, R. Schneider, Angew. Chem.
99 (1987) 1059; Anqew. Chem. Int. Ed. Engl. 26 (1987) 1029. hexane:CH2Cl2 = 5:1, 12.5 ml/min) to give 2.47 g of an isomer I
51 M) H. Mayr, Anqew.. 93 (1981) 202; Angew. Chem. Int. Ed. with R{ = 8.7 min and 0.89 g of an isomer II with R, = 9.7 min.
Enql. 20 (1981) 184. - 5b) H. Mayr, W. Striepe, J. Org. Chem.
— 2,4-Dinitrophenylhydrazone of 14b (isomer I): M.p. 147 —148°C
48 (1983) 1159.
(hexane/CH2Ci2). - 'H NMR (CDC13): 6 = 1.14 (t, J = 7.5 Hz,
616al K. Yamamoto, O. Nunokawa, J. Tsuji, Synthesis 1977, 721.
3H, CH3), 1.24 (t, J = 1A Hz, 3H, CH3), 2.60 (q, J = 7.5 Hz, 2H, - 6bl T. H. Chan, P. W. K. Lau, W. Mychajlowskij, Tetrahedron
Lett. 1977, 3317. - 6c) K. Yamamoto, J. Yoshitake, N. T. Qui,
CH2), 2.63 (q, J = 7.4 Hz, 2H, CH2), 11.26 (br. s, 1H, NH), aryl H
J. Tsuji, Chem. Lett. 1978, 859. - 6d) K. Yamamoto, M. Ohta,
as usual. - 13C NMR (CDC13): 5 = 12.63 (q), 13.90 (q), 21.51 (t),
J.,.. 1979, 713.
29.91 (t), 116.6 (d), 123.5 (d), 129.4 (s), 130.0 (d), 132.3 (s), 138.2 (s),
71 G. A. Olah. Y. Halpern, Y. K. Mo, G. Liang, J. Am. Chem. Soc.
144.3 (s), 144.8 (s), 147.2 (d). 94 (1972) 3554.
8) H. Hogeveen. H. Jorritsma, P. A. Wade, Tetrahedron Lett. 1974,
C13H15C1N404 (326.7) Calcd. C 47.79 H 4.63
( 3915.
Found C 47.91 H 4.68 91 Organikum. Organisch-Chemisches Grundpraktikum, 15th edition,
p. 484, VEB Deutscher Verlag der Wissenschaften, Berlin 1977.
2,4-Dinitrophenylhydrazone of 14b (isomer II): M.p. 154 —156"C
(hexane/CH2Cl2). - 'H NMR (CDC13): 5 = 1.13 (t, J = 7.5 Hz, [236/87]
Chem. Ber. 121, 191 -193 (1988)