Abstract: | Two new halogenated sesquiterpenes, (8β)‐10‐bromo‐3‐chloro‐2,7‐epoxychamigr‐9‐en‐8‐ol ( 1 ) and 2‐bromo‐3‐chlorobisabola‐7(14),11‐diene‐6,10‐diol ( 3 ), and one new phytol‐derived diterpene, 2,3‐epoxyphytyl acetate ( 4 ), along with cis‐ and trans‐1‐methylcyclohexane‐1,4‐diol ( 5 and 6 ) which were isolated from a natural source for the first time but have been previously synthesized, were isolated from the marine red alga Laurencia composita and characterized. In addition, a known sesquiterpene, pacifenediol ( 2 ), and the known furanone derivative 7 were also identified. Their structures were established by NMR and mass spectroscopic methods. |