Collect. Czech. Chem. Commun. 1990, 55, 1783-1791

Synthesis of 5-methyl-19-nor-5β-pregn-9-ene derivatives

Jiří Polman and Alexander Kasal

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


3β,5,6β-Trihydroxy-5α-pregnan-20-one 3-pivalate (I) was converted into 3β,6β-dihydroxy-5-methyl-19-nor-5β-pregn-9-en-20-one 3-pivalate 5-acetate (II) under conditions of Westphalen rearrangement. Deoxygenation in the position 6β was effected by treatment of the corresponding 6β-thiobenzoate or thioimidazolide with tributyltin hydride. Progesterone analogues XII and XIII, prepared from the 6-deoxy compound IX, exhibit abortive activity.