14-methyl steroids. Part 3. Synthesis of (±)-14α-methyl-9β-estradiol and related 14α-methyl-19-norsteroids

Catalytic hydrogenation of a totally synthetic mixture of (±)-3-methoxy-14-methyl-14α-estra-1,3,5( 10), 9(11)-tetraen-17-one(1) and the corresponding 1,3,5(10),8-tetraen-17-one (2) gives a mixture of 14α-methyl-8β,9β-, -8α,9α-, and -8β,9α-estrones, which is converted into the 17β-hydroxy-mixtures. t-Butylation gives a separable mixture of the three isomers, of which (±)-17β-t-butoxy-3 methoxy-14-methyl-9β,14α-estra-1,3,5(10)-triene(6) is the major component. The corresponding 14α-methylestradiols are prepared. A practical synthesis of (±)-14-methyl-14α-estra-1,3,5(10), 6,8-pentaene-3,17β-diol(25) is described, and it is shown that DDQ dehydrogenation of 1,3,5(10),9(11)-tetraenes in this series leads exclusively to the corresponding 1,3,5(10),6,8,11-hexaenes, whereas that of 1,3,5(10),8-tetraenes gives only 1,3,5(10),6,8-pentaenes.