18-Deoxyaldosterone,its chemical and microbial reduction products

Reduction of the diketal 1 with sodium aluminum bis-(methoxyethoxy) hydride afforded the crystalline 18-hydroxycorticosterone diketal (2), an intermediate in the formation of 18-deoxyaldosterone acetate (4b). The hitherto unreported but anticipated metabolites of 4 were prepared as follows: hydrogenations of 4b furnished the fα- and 5β isomers 6 and 5b, and thence the tetra- and hexahydro derivatives 10, 11, 8, 9 and 7, and the 3-deoxy compounds 12 and 13. Anaerobic fermentations of 4b with Clostridium paraputrificum gave the tetrahydro derivative 8b in high yield.