The title compounds (16α-carboxymethyl-3α-hydroxy-5α-pregnan-20-one and its sodium and triethylammonium salts) were prepared from 20-oxopregna-5,16-dien-3β-yl acetate by conjugate addition of dimethyl malonate and decarboxylation. Inversion of configuration at carbon C-3 was carried out by Mitsunobu acylation with diethyl azodicarboxylate and formic acid in the presence of triphenylphosphine.