Cyclization of Epoxyneocembrene Derivatives to Secotrinervitanes

Article abstract of DOI:10.1021/jo00014a036

Four stereoisomers of epoxyneocembrene derivatives 5-8 were treated with BF3*OEt2 as potential model reactions for the proposed biogenesis of secotrinervitane-type diterpenoids (Scheme I).Two of them (5 and 6) afforded secotrinervitane derivatives, while the remaining isomers 7 and 8 gave no cyclization products (Table I).The natural product, secotrinervitene-2β,3α-diol (2a) was synthesized from 5 in dl-form.