(−)-Paniculatol, a new ent-labdane bromoditerpene from Laurencia paniculata

Abstract

(−)-Paniculatol, 1, an unusual tricyclic bromoditerpene belonging to the ent-labdane series has been identified in the red alga Laurencia paniculata collected on Qatari coasts, Arabian Gulf. The structure displays an unusual tetrahydropyran ring and the absolute configuration has been determined by X-ray crystallography.