(5R-(5 alpha,10 alpha,10a alpha,14a alpha,15b alpha))-1,10,10a,14,14a,15b-hexahydro-10,10a- dihydroxy-7-methoxy-2,2-dimethyl-5-(2-methyl-1-propenyl)-5H,12H-3,4-dioxa-5a,11a,15a-triaza cyclooct (1m) indeno (5,6-b)fluorene-11,15(2H,13H)- dione