1H-Naphth[2',1':4,5]indeno[2,1-b]furan, pregn-17(20)-en-21-oic acid deriv. 337-67-7 5.alpha.-Pregn-17(20)-en-21-oic acid, 3.beta.,16.beta.-dihydroxy-11-oxo-, .gamma.-lactone 5.alpha.-Pregn-17(20)-en-21-oic acid, 3.beta.,16.beta.-dihydroxy-11-oxo-,-lactone NSC66816 Pregn-17(20)-en-21-oic acid, 3,16-dihydroxy-11-oxo-, .gamma.-lactone, (3.beta.,5.alpha.,16.beta.)-