Rogiolol Acetate: A Novel β‐Chamigrene‐Type Sesquiterpene Isolated from a Marine Sponge

The marine sponge Spongia zimocca S CHMIDT , 1862, collected in front of the torrent II Rogiolo, south of Livorno, contains the sesquiterpene rogiolol acetate (= (+)‐(2R, 3 S, 6 R, 8 R, 9 R)‐ 2 , 8 ‐ dibromo ‐ 9 ‐ chloro ‐ 1 , 1 , 9 ‐ trimethyl ‐ 5 ‐ methylidenespiro [ 5.5 ] undec ‐ 3 ‐ yl acetate ; (+)‐ 3a ), which represents the first chamigrane isolated from a sponge. Although compounds of this class are common in red seaweeds of the genus Laurencia , and our sponge actually contains 9‐bromochamigrene and a variety of other metabolites of nearby growing Laurencia sp., (+)‐ 3a is unique to our sponge.