作者:David A. Jackson、Max Rey、Andr� S. Dreiding
DOI:10.1002/hlca.19850680217
日期:1985.3.27
· Et2O- and the CH3SO3H-catalysed rearrangements of 10 α-vinylcyclobutanones have been examined. With little acid, the β,β-dialkyl derivatives 1 were transformed into linear dienones 2 and 3; with more acid, they were converted into cyclopentenones 4 by Nazarov cyclisation of initially formed 2/3. The β-monoalkyl (including the β,γ-dialkyl) derivatives 7 rearranged only with a high acid concentration
研究了BF 3 ·Et 2 O-和CH 3 SO 3 H催化的10个α-乙烯基环丁酮的重排。用很少的酸,将β,β-二烷基衍生物1转化为线性二烯酮2和3。随着更多的酸,他们通过最初形成的2/3的纳扎罗夫环化反应被转化为环戊烯4。β-单烷基(包括β,γ-二烷基)衍生物7仅在高酸浓度下重排以通过1,2-酰基迁移得到环戊烯酮8。在7a的情况下,环戊烯酮在图8a中伴随着意外的结构异构体9a,这可以通过环丁酮7a与它的异构体19经由环丙烷中间体18的可逆相互转化来解释。在含有α-异丁烯基(而不是α-乙烯基)的β,β-二烷基衍生物5的情况下,酸催化的重排产物为双环[3]。1. 0]己酮衍生物6。