Regioselectivity in gas-phase elimination reactions: 1,2 vs 1,4 and allenic ion vs dienide formation
作者:John J. Rabasco、Steven R. Kass
DOI:10.1016/0040-4039(93)89006-c
日期:1993.1
Gas-phase elimination reactions of deuterium labeled 1-allyl-1-methoxy-6,6-dimethyl-2-cyclohexene (1), 1-methoxy-4,4-dimethyl- 1-vinyl-2-cyclohexene (2) and 3-methoxy-3-methyl-1-butene (3) have been investigated. 1,2-Elimination is the favored pathway when 1 reacts with hydroxide (3.5:1) and methoxide (2.6:1), but 1,4-elimination is preferred with fluoride by 2:1. Abstraction of a vinyl proton in the
氘标记的1-烯丙基-1-甲氧基-6,6-二甲基-2-环己烯(1),1-甲氧基-4,4-二甲基-1-乙烯基-2-环己烯(2)和已经研究了3-甲氧基-3-甲基-1-丁烯(3)。当1与氢氧化物(3.5:1)和甲醇盐(2.6:1)反应时,1,2-消除是有利的途径,但氟化物优选2:1消除1,4-消除。当使用酰胺和/或二甲酰胺时,在2和3的消除反应中,乙烯基质子的提取占主导地位,而氢氧化物在很大程度上有利于烷基质子的损失。