2-Butenoic acid, 2-methyl-, 2,4,4a,5,6,7,8,8a,9,9a-decahydro-3,4a,5-trimethyl-2-oxonaphtho(2,3-b)furan-6-yl ester, (4aS-(4aalpha,5alpha,6alpha(Z),8aalpha,9abeta))- 70773-67-0 73209-21-9