PREPARATION AND REARRANGEMENT OF 1,2-DIALKENYLCYCLOBUTANOLS - A USEFUL METHOD FOR SYNTHESIS OF SUBSTITUTED CYCLOOCTENONES
PREPARATION AND REARRANGEMENT OF 1,2-DIALKENYLCYCLOBUTANOLS - A USEFUL METHOD FOR SYNTHESIS OF SUBSTITUTED CYCLOOCTENONES
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DOI：
10.1021/jo00133a007
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发表时间：
1982-01-01
影响因子：
3.6
通讯作者：
LETT, RM
中科院分区：
文献类型：
--
作者：
GADWOOD, RC;LETT, RM
报道了1，2-二烯基环丁醇的合成和阴离子氧-Cope重排[用于天然产物的合成]。2-甲基-2-（2-甲基丙烯-1-基）-1-环丁酮与乙烯基锂、异丙烯基锂或异丁烯基锂的反应导致形成环丁醇2a-c。用氢化钾处理诱导重排为Z和E环辛烯酮3a-c和4a，c。5-亚甲基螺[3.5]壬-1-酮与相同的烯基锂试剂反应，直接得到重排和开环产物的混合物。螺[3.5]壬-5-烯-1-酮与乙烯基-或异丙烯基溴化镁反应产生非对映体环丁醇18 a、B和19 a、B的混合物，其经历阴离子氧-Cope重排成双环[5.3.1.]十一碳-1-（11）-烯-4-酮20 a，B的高产率。提出了立体远位1，2-二烯基环丁醇重排反应的机理。
The syntheses and anionic oxy-Cope rearrangements of 1,2-dialkenylcyclobutanols are reported [for natural product syntheses]. Reaction of 2-methyl-2-(2-methylpropen-1-yl)-1-cyclobutanone with vinyl-, isopropenyl-, or isobutenyllithium led to formation of cyclobutanols 2a-c. Treatment with potassium hydride induced rearrangement to Z and E cyclooctenones 3a-c and 4a,c. Reaction of 5-methylenespiro[3.5]nonan-1-one with the same alkenyllithium reagents afforded directly a mixture of rearranged and ring-opened products. Reaction of spiro[3.5]non-5-en-1-one with vinyl- or isopropenylmagnesium bromide produced a mixture of diastereomeric cyclobutanols 18a,b and 19a,b which underwent anionic oxy-Cope rearrangement to bicyclo[5.3.1.]undec-1-(11)-en-4-ones 20a,b in high yield. A mechanism for the rearrangement of stereodistal 1,2-dialkenylcyclobutanols is proposed.