Rapid stereoselective access to the tetracyclic core of puupehenone and related sponge metabolites using metal-free radical cyclisations of cyclohexenyl-substituted 3-bromochroman-4-ones
作者:Robin G. Pritchard、Helen M. Sheldrake、Isobel Z. Taylor、Timothy W. Wallace
DOI:10.1016/j.tetlet.2008.04.114
日期:2008.6
The tetracyclic nucleus of puupehenone, 15-oxopuupehenol and other sesquiterpene–phenol natural products can be assembled stereoselectively in three steps, the last of these being the 6-endo-trig cyclisation of an alpha-keto radical generated from a substituted 2-(2-cyclohexenyl)ethyl 3-bromo-4-chromanone under metal-free conditions.
puupehenone,15- oxopuupehenol和其它倍半萜烯-苯酚天然产物的四环核可以立体选择性地在三个步骤中被组装,最后这些作为6-内- trig的从生成的α-酮基团的环化的取代的2-(2- -环己烯基)乙基3-溴-4-苯并二氢吡喃酮在无金属的条件下。