2-Butenoic acid, 2-methyl-, 2,4,4a,5,6,7,8,8a,9,9a-decahydro-4-hydroxy-3,4a,5-trimethyl-2-oxonaphtho(2,3-b)furan-6-yl ester, (4S-(4alpha,4abeta,5beta,6alpha(Z),8abeta,9aalpha))- 73171-27-4