A complete synthesis is reported for the racemic forms of all four possible cis- and trans-B/C-DELTA-5(10),15-rosadienes using electrophilic cyclization of their regular A,B-seco precursors in the final step.
3-Substituted 1-vinyl-1-methylcyclohex-3-enes ? Precursors of tricyclic diterpenoids of the pimarane/rosane group
摘要:
The synthesis of 1-vinyl-1-methyl-3-chloromethylcyclohex-3-ene from 3-vinyl-3-methylcyclohexanone and the corresponding exomethylene derivative has been optimized and related allylsulfones prepared. By a standard combination of these compounds with the appropriate (cyclo)geranyl block synthones a series of regular functionalized diterpenoids has been prepared which are considered as likely precursors of the natural compounds indicated in the title.