(R)-1,3-dimethylcyclopropene—one isomer of the smallest chiral hydrocarbon
摘要:
1-Lithio-1,3-dimethylcyclopropene has been obtained in optically active form in five steps from tiglic acid and trapped with electrophiles to produce, among others, optically active 1,3-dimethylcyclopropene.
Highly diastereoselective approach to methylenecyclopropanes via boron-homologation/allylboration sequences
作者:A. N. Baumann、A. Music、K. Karaghiosoff、D. Didier
DOI:10.1039/c5cc09904h
日期:——
A simple and efficient diastereoselective synthesis of methylenecyclopropanes is described, in which boron-homologation and allylboration are merged into a one-pot process, starting from in-situ generated cyclopropenyllithium species. This unprecedented methodology...
1-halocyclopropenes and propargylic halides from the reaction of trihalocyclopropanes with methyl lithium
作者:Mark S. Baird、William Nethercott
DOI:10.1016/s0040-4039(00)81476-8
日期:1983.1
1,1,2-Trihalocyclopropanes (halogen = chlorine or bromine) undergo 1,2-dehalogenation on reaction with methyl lithium, and in a number of cases the product is a 1-halocyclopropene. In the reactions of (20, X = Br, Cl) and (25) a rearrangement occurs even at low temperatures and propargylic halides are isolated, while (16) is converted to 2-chlorocyclohex-2-enylidene which may be trapped by furan.
Optically active dihydropyrans and 3-methylenetetrahydrofurans from cyclopropenylethanol derivatives
作者:Juma'a R.Al-Dulayymi、Mark S. Baird
DOI:10.1016/s0040-4020(01)87769-3
日期:1990.1
Reaction of a number of 2-(cycloprop-1-en-1-yl)ethanol derivatives with bromine, acid or silver ion leads to ring expansion, either to 5,6-dihydro 2H-pyrans or to 3-methylenetetrahydrofurans.
Semipinacol Rearrangement of Cyclopropenylcarbinols for the Synthesis of Highly Substituted Cyclopropanes
作者:Vladyslav Smyrnov、Jerome Waser
DOI:10.1021/acs.orglett.3c02543
日期:2023.9.29
cyclopropenylcarbinols is reported. This transformation gives access to various polyfunctionalized cyclopropanes under mild metal-free conditions. The scope of the reaction includes iodine, sulfur and selenium electrophiles, aryl and strained ring migrating groups, and diverse substitution patterns on the cyclopropene. The reaction is particularly efficient for the synthesis of small ring-containing spirocycles, which