Functional group hybrids. Reactivity of .alpha.'-nucleofuge .alpha.,.beta.-unsaturated ketones. 1. Reactions with organocopper reagents
摘要:
A series of alpha-nucleofuge alpha',beta'-unsaturated ketones encompassing a variety of structural types and nucleofuges was prepared. Treatment of these compounds with lithium dimethylcuprate or methylcopper leads primarily to either reductive cleavage of the alpha-nucleofuge or conjugate addition. Good alpha-nucleofuges favored the reduction pathway while poorer nucleofuges favored conjugate addition.
Functional group hybrids. Reactivity of .alpha.'-nucleofuge .alpha.,.beta.-unsaturated ketones. 2. Reactions with malonate anion. Concerning the mechanism of the Favorskii rearrangement
作者:Thomas R. Barbee、Hedeel Guy、Mary Jane Heeg、Kim F. Albizati
DOI:10.1021/jo00024a015
日期:1991.11
The scope and limiations of the reaction of alpha'-nucleofuge alpha,beta-unsaturated ketones with sodium dimethyl malonate has been studied systematically. The substrates with good nucleofuges (halides, mesylate) give cyclopropanols upon reaction with malonate anion by way of a conjugate Favorskii reaction. In reactions with substrates containing the poorer nucleofuge (acetoxy) conjugate addition proceeded without entering the Favorskii manifold. Concerning the mechanism of the Favorskii reaction, it is suggested that the loss of the nucleofuge occurs to give a 2-oxyallyl cation, but that disrotatory ring closure is facile and the only products observed result from nucleophilic trapping of cyclopropanones to yield cyclopropanols in fair to good yield.
Functional group hybrids. Reactivity of .alpha.'-nucleofuge .alpha.,.beta.-unsaturated ketones. 1. Reactions with organocopper reagents
作者:Thomas R. Barbee、Kim F. Albizati
DOI:10.1021/jo00024a014
日期:1991.11
A series of alpha-nucleofuge alpha',beta'-unsaturated ketones encompassing a variety of structural types and nucleofuges was prepared. Treatment of these compounds with lithium dimethylcuprate or methylcopper leads primarily to either reductive cleavage of the alpha-nucleofuge or conjugate addition. Good alpha-nucleofuges favored the reduction pathway while poorer nucleofuges favored conjugate addition.
Photochemistry of Chlorinated 2-Cycloalkenones
作者:Isabelle Altmeyer、Paul Margaretha
DOI:10.1002/hlca.19770600316
日期:1977.4.20
The 6-chloro-2-cyclohexenones 3, 6 and 11, and the 5-chloro-2-cyclopentenone 15 were newly synthesized. The results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs. cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ -position of the enone. No oxetanes are formed in the intramolecular photocycloaddition of 6. Compound