77769-45-0Relevant articles and documents
Reactions between Furyl Ketones and Grignard Reagents. II. Steric Effects in the Reactions of 2-Furyl Ketones with Alkylmagnesium Halides
Sjoeholm, Rainer,Woerlund, Krister
, p. 435 - 442 (2007/10/02)
The effect of steric crowding at the carbonyl carbon of some alkyl 2-furyl ketones, 2-Fur-CO-R (R = Et, i-Pr, and t-Bu), on the reaction with alkyl Grignard reagents, R'MgX (R' = Me, i-Pr, and t-Bu), has been studied.The effect of the size of the alkyl group of the Grignard reagent was also considered.When MeMgI reacts with the ketones only 1,2-addition products are formed.Reactions with i-PrMgCl and t-BuMgCl give considerable amounts of 1,4- and 1,6-addition products besides 1,2-addition.The primary conjugate addition products are easily oxidized to alkyl substituted alkyl 2-furyl ketones and 2-(5H)-furanones when exposed to air.Further, the i-Pr reagent gives reaction products formed by reduction of the carbonyl group.An increase in the amount of conjugate addition products is observed when the size of the alkyl group in the substrate or that of the alkyl group of the reagent is increased.Possible reaction mechanism are discussed.