Preparation and decomposition of some steroidal 4′β,5′-dihydro-[17α,16-c]pyrazoles

Abstract

Reaction of a series of aliphatic diazo-compounds with Δ¹⁶-20-oxo-steroids has given the corresponding 4′,5′-dihydro-[17α,16α-c]pyrazoles ([17α,16α-c]pyrazolines). Pyrolysis of the pyrazolines gave in the cases where the substituent on the heterocyclic ring is unsaturated, the 1′β,3′-dihydrocyclopropa[16,17α]-compounds (8) and (9). Pyrolysis of the pyrazolines with a saturated substituent on the heterocyclic ring gave a mixture of the Δ¹⁶-16-alkyl- and the 1′β,3′-dihydrocyclopropa[16,17α]-compounds. Photolytic decomposition of the pyrazolines gave only the cyclopropa[16α,17α]-compounds.