(3bR,6aS)-hexahydro-5,5-dimethyl-N-[(S)-α-methylbenzyl]-6a-methyl-3a-(1,3-benzodioxole-5-yl)-3-carboethoxy-[1,3]dioxolo[3,4]cyclopent[1,2-c]isoxazole

(3R,3aS,7aS)-N-formal-3-(pivaloyloxy)-3a-[3,4-(methylenedioxy)phenyl]-2,3,3a,6,7,7a-hexahydroindol-6-one