Studies of Australian soft corals. XIX. Two new sesquiterpenes with the nardosinane skeleton from a Paralemnalia species

Abstract

The isolation of two new sesquiterpenes (3) and (4), related to the known sesquiterpenes lemnalactone(1) and 2-deoxylemnacarnol (5), is reported from the soft coral Paralemnalia thyrsoides. Their structures were deduced from spectroscopic data, and confirmed by conversion into known sesquiterpenes. A semisystematic nomenclature, based on the name 'lemnalan' for the trimethylperhydronaphtho[b]furan (8) parent structure, is suggested.