Synonyms: Butanoicacid, 2-methyl-,3-[(acetyloxy)methyl]-1,1a,1b,4,4a,5,7a,7b,8,9-decahydro-4a,7b-dihydroxy-1,1,6,8-tetramethyl-5-oxo-9aH-cyclopropa[3,4]benz[1,2-e]azulen-9a-ylester, [1aR-(1aa,1bb,4ab,7aa,7ba,8a,9b,9aa)]- (9CI); Butyric acid,2-methyl-, 9a-ester with 1,1aa,1bb,4,4a,7aa,7b,8,9,9a-decahydro-4ab,7ba,9aa-trihydroxy-3-(hydroxymethyl)-1,1,6,8a-tetramethyl-5H-cyclopropa[3,4]benz[1,2-e]azulen-5-one3-acetate (8CI); 5H-Cyclopropa[3,4]benz[1,2-e]azulen-5-one, 1,1aa,1bb,4,4a,7aa,7b,8,9,9a-decahydro-4ab,7ba,9aa-trihydroxy-3-(hydroxymethyl)-1,1,6,8a-tetramethyl-, 3-acetate9a-(2-methylbutyrate) (8CI); 9aH-Cyclopropa[3,4]benz[1,2-e]azulene, butanoicacid deriv.; 13-O-([2-Methyl]-2-butyryl)-12-deoxyphorbol 20-acetate