Synonyms: 2-Butenoic acid, 3-methyl-, (1R,2E,4S,6Z,9E,11R)-11-hydroxy-7-(hydroxymethyl)-4,11-dimethyl-4-(4-methyl-3-penten-1-yl)-8-oxo-2,6,9-, 2-Butenoic acid, 3-methyl-, (1R,2E,4S,6Z,9E,11R)-11-hydroxy-7-(hydroxymethyl)-4,11-dimethyl-4-(4-methyl-3-pentenyl)-8-oxo-2,6,9-cycloundecatrien-1-yl ester (9CI); 2-Butenoic acid, 3-methyl-, 11-hydroxy-7-(hydroxymethyl)-4,11-dimethyl-4-(4-methyl-3-pentenyl)-8-oxo-2,6,9-cycloundecatrien-1-yl ester, [1R-(1R*,2E,4S*,6Z,9E,11R*)]-; Cycloundecane, 2-butenoic acid deriv.; Vibsanin BDouble bond geometry as shown., Absolute stereochemistry.