Synonyms: Spiro[furo[3,2-b]furan-2(3H),9'-[3,7]methanofuro[2,3-b]oxepin]-7'(6'H)-carboxylicacid,6'-(3-furanylcarbonyl)-2',3',3a,3'a,5,6,6a,8'a-octahydro-3',6',8'a-trimethyl-3a-(1-methylethenyl)-2',5-dioxo-,methyl ester, [3'S-[3'a,3'ab,6'b,7'b,8'ab,9'R*(3aS*,6aR*)]]-; (-)-BrowninB; Brownin B