Synthesis and some properties of gem-dichlorocyclopropane carboxaldehyde acetals and cyclopropane carboxaldehyde acetals

Khusid, A. Kh.; Kryshtal, G. V.; Dombrovsky, V.A.; Kucherov, V. F.; Yanovskaya, L. A.; Kadentsev, V. I.; Chizhov, O. S.

doi:10.1016/0040-4020(77)80436-5

Cited by 15 publications

(7 citation statements)

References 6 publications

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“…Starting aldehydes, if not commercially available, were prepared by PCC oxidation of the corresponding primary alcohols. 1,1-Dimethoxyhexane, 1,1-dimethoxy-3,7-dimethyloctane, 2-benzyloxytetrahydropyran, 2-cyclohexyl-1,1-dimethoxyethane, 1,1-dimethoxy-3-phenylpropane, 1,1-dimethoxy-2-ethylhexane, 1,1-dimethoxy-3,3-dimethylbutane, and 2-cyclopropyl-1,1-diethoxyethane were prepared according to the literature. New acetals 10-acetoxy-1,1-dimethoxydecane, 3-cyclohexyl-1,1-dimethoxypropane, and 1,1-dimethoxy-3-ethyl-heptane were prepared by acetalization of the correspondimg aldehydes with excess MeOH or CH(OMe) 3 in the presence of p -toluenesulfonic acid ( 1 H and/or 13 C NMR spectra are included in the Supporting Information).…”

Section: Methodsmentioning

confidence: 99%

Novel Preparation of α,β-Unsaturated Aldehydes. Benzeneselenolate Promotes Elimination of HBr from α-Bromoacetals

Васильев

Engman

2000

J. Org. Chem.

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Acetalization, alpha-bromination, nucleophilic phenylselenenylation, oxidative elimination/hydrolysis was investigated as a novel protocol for the alpha,beta-dehydrogenation of aldehydes. Treatment of acetals with bromine in methylene chloride afforded the corresponding alpha-bromoacetals in 80-90% yields. Nucleophilic phenylselenenylation was then conveniently effected by treatment with benzeneselenolate generated in situ in dimethyl sulfoxide from diphenyl diselenide, hydrazine and potassium carbonate. Unbranched alpha-bromoacetals cleanly afforded substitution products whereas beta- and gamma-branched ones gave substantial amounts of alpha,beta-unsaturated acetals via formal loss of hydrogen bromide. Oxidative elimination/hydrolysis of these mixtures afforded alpha,beta-unsaturated aldehydes in 50-80% overall yields. In the case of tertiary alpha-bromoacetals, treatment with benzeneselenolate afforded only dehydrobromination products as mixtures of isomers. The presence of at least a catalytic amount of the organoselenium reagent was found to be crucial for olefin formation. A SET-mechanism, involving benzeneselenolate-induced electron transfer to the halide, loss of bromide ion, and hydrogen atom or proton/electron was proposed for the benzenselenolate-promoted elimination reaction. Experiments designed to trap carbon-centered radicals in intramolecular cyclization or ring-opening reactions failed to provide any evidence for free-radical intermediates.

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Section: Methodsmentioning

confidence: 99%

Novel Preparation of α,β-Unsaturated Aldehydes. Benzeneselenolate Promotes Elimination of HBr from α-Bromoacetals

Васильев

Engman

2000

J. Org. Chem.

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“…However, in special cases, for example, the 2-fold cyclopropanation with dichlorocarbene of 533 , endowed with particularly electron-rich terminal double bonds, the bisadduct 534 was formed in very good yield (Scheme ) . In other cases, mixtures of regioisomers were obtained 86 …”

Section: Branched Aggregates Of Three-membered Ringsmentioning

confidence: 99%

“…[360][361][362][363] 1,2-Dicyclopropylethenes have also been obtained by the addition of carbenes or carbenoids to 1,3,5-hexatrienes. [364][365][366][367][368] In many cases, the terminal double bonds are cyclopropanated selectively, and the second cyclopropanation (especially with dihalocarbenes) is much slower than the first one, which causes low yields of the bisadducts (Scheme 86). 367 However, in special cases, for example, the 2-fold cyclopropanation with dichlorocarbene of 533, endowed with particularly electron-rich terminal double bonds, the bisadduct 534 was formed in very good yield (Scheme 86).…”

Section: Oligocyclopropyl-substituted Alkanes Alkenes and Alkynesmentioning

confidence: 99%

“…367 However, in special cases, for example, the 2-fold cyclopropanation with dichlorocarbene of 533, endowed with particularly electron-rich terminal double bonds, the bisadduct 534 was formed in very good yield (Scheme 86). 365 In other cases, mixtures of regioisomers were obtained. 365 The ethylene derivative 538, being the sterically most encumbered alkene ever synthesized, was prepared by thermal decomposition of the thiadiazoline formed by thermal [2 + 3] cycloaddition of 535 and 536 and subsequent sulfur extrusion from the resulting thiirane 537 (Scheme 87).…”

Section: Oligocyclopropyl-substituted Alkanes Alkenes and Alkynesmentioning

confidence: 99%

“…365 In other cases, mixtures of regioisomers were obtained. 365 The ethylene derivative 538, being the sterically most encumbered alkene ever synthesized, was prepared by thermal decomposition of the thiadiazoline formed by thermal [2 + 3] cycloaddition of 535 and 536 and subsequent sulfur extrusion from the resulting thiirane 537 (Scheme 87). 369 The attempted catalytic hydrogenation of 538 to yield tetrakis-(tert-butyl)ethene (539) proved to be unsuccessful, just as the attempted direct synthesis of this latter compound 539 along the same lines.…”

Section: Oligocyclopropyl-substituted Alkanes Alkenes and Alkynesmentioning

confidence: 99%

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Three-Membered-Ring-Based Molecular Architectures

2006

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Simmons‐Smith Cyclopropanation Reaction

2001

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Almost 30 years after Emschwiller prepared IZnCH 2 I, Simmons and Smith discovered that the reagent formed by mixing a zinc‐copper couple with CH 2 I 2 in ether could be used for the stereospecific conversion of alkenes to cyclopropanes. Nowadays, the Simmons‐Smith cyclopropanation reaction is one of the most widely used reactions in the organic chemist's arsenal for the conversion of olefins into cyclopropanes. This popularity is mainly due to the stereospecificity of the reaction with respect to the double bond geometry and its compatibility with a wide range of functional groups. The chemoselectivity of the reaction toward some olefins is excellent and very few side reactions are observed with functionalized substrates. The metal carbenoid is electrophilic in nature and electron‐rich alkenes usually react much faster than electron‐poor alkenes. Furthermore, the ability to use proximal hydroxy or ether groups to dictate the stereochemical outcome of the CC bond forming process was recognized early on, and this unique property has been successfully exploited on numerous occasions. It has been recognized that halomethylmetal reagents are powerful synthetic tools for the stereoselective addition of a methylene unit to chiral acyclic allylic alcohols and allylic ethers. In addition, the use of halomethylzinc reagents in the presence of chiral additives is one of the few ways to cyclopropanate allylic alcohols efficiently and with good enantiocontrol. Carbenoids can be divided into the following two classes: (1) those of general structure MCH 2 X and (2) those corresponding to M = CH 2 . This chapter is focussed exclusively on the first class in which M = Zn, Sm, or Al. Although other metal carbenoids of type MCH 2 X, such as those derived from Cu, Cd, Hg, and In, have been reported to be effective reagents for the cyclopropanation of some olefins, they have been used only sporadically, and this review does not highlight these reactions. This chapter covers cyclopropanation reactions involving haloalkylzinc, aluminum, and samarium reagents published since the comprehensive chapter in Organic Reactions by Simmons that surveyed the literature up to 1973.

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Synthesis and some properties of gem-dichlorocyclopropane carboxaldehyde acetals and cyclopropane carboxaldehyde acetals

Cited by 15 publications

References 6 publications

Novel Preparation of α,β-Unsaturated Aldehydes. Benzeneselenolate Promotes Elimination of HBr from α-Bromoacetals

Novel Preparation of α,β-Unsaturated Aldehydes. Benzeneselenolate Promotes Elimination of HBr from α-Bromoacetals

Three-Membered-Ring-Based Molecular Architectures

Simmons‐Smith Cyclopropanation Reaction

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