bis-allylic reactivity of the funicolides, 5,8(17)-diunsaturated briarane diterpenes of the sea pen Funiculina quadrangularis from the Tuscan archipelago, leading to 16-nortaxane derivatives

Article abstract of DOI:10.1002/hlca.19950780606

Funicolides A-C (1-3), D (5), and E (7) and 7-epifunicolide A (4), new 5,8(17)-diunsaturated briarane diterpenes, as well as the known analogue brianthein W (6), were isolated from the pennatulacean coral Funiculina quadrangularis (Pallas, 1766) collected in the Tuscan archipelago. Easy degradation under oxidative and/or basic conditions served to assign the ester groups at C(2) or C(14), while revealing bis-allylic reactivity at C(7) with formation of 16-nortaxane derivatives.