(6a'R,8a'S,8b'S,9a'R,10a'S,10b'R)-6a',8a'-Dimethyl-8b'-(2-methyl-1,3-dioxolan-2-yl)-1',2',5',6',6a',6b',7',8',8a',8b',9a',10',10a',10b'-tetradecahydrospiro[[1,3]dioxolane-2,4'-naphtho[2',1':4,5]indeno[1,2-b]oxirene] is an intermediate in the synthesis of 16β-Methyl-17α,21-Dihydroxypregna-1,4-diene-3,20-dione (M302195). 16β-Methyl-17α-Dihydroxypregna-1,4-diene-3,20-dione is an intermediate in the synthesis of 17,21-dihydroxy-16β-methylpregna-1,4-diene-3,20-dione (D434280), a corticoid with the potential for ant-inflammatory activity.