Patent ID: 8658788

Claim:
A process for the production of a 3-oxo-pregn-4-ene-21,17-carbolactone of formula III: in which R 6a is hydrogen or together with R 7a a —CH 2 group; R 6b is hydrogen or together with R 7b a —CH 2 -group; R 7a is hydrogen, C 1 -C 4 -alkyl, C 1 -C 4 -alkoxycarbonyl, C 1 -C 4 -thioacyl or together with R 6a a —CH 2 -group; R 7b is hydrogen or together with R 6b a —CH 2 -group; R 9 is hydrogen, together with R 11 a double bond, or together with R 11 an epoxy group —O—; R 10 is hydrogen, methyl, or ethyl; R 11 is hydrogen, together with R 9 a double bond or together with R 9 an epoxy group —O—; R 13 is hydrogen, methyl or ethyl; R 15 is hydrogen, C 1 -C 4 -alkyl or, together with R 16 , a —CH 2 -group or a double bond; R 16 is hydrogen or, together with R 15 , a —CH 2 -group or a double bond; comprising: a) reacting a compound of formula I in which R 5 is hydroxy; and R 6a , R 6b , R 7a , R 7b , R 9 , R 10 , R 11 , R 13 , R 15 , R 16 have the same meaning as in formula III, with at least 3 molar equivalents of an organic or inorganic hypochlorite as an oxidizing agent in the presence of a catalytic amount of a 2,2,6,6-tetramethylpiperidine-N-oxide derivative at a pH of at least 8.0, to form a compound of formula II: and b) subsequently converting the compound of formula II to a compound of formula III.