Title:Construction of a γ-Butyrolactone Moiety: A Facile Synthesis of 3β- Hydroxy-5,6-Dihydro-17β -Methoxy-Pregnan-21,16α-Carbalactone - a New D-Ring Fused Steroidal γ-Butyrolactone from an Abundant 20- Oxopregnane using Metal Mediated Halogenation as the Key Step
Volume: 12
Issue: 8
Author(s): Preetismita Borah, Ashma Begum, Saroj Hazarika and Pritish Chowdhury
Affiliation:
Keywords:
γ-Butyrolactones, D-ring fused Steroidal γ-Butyrolactones, Antitumor Steroids, 5α, 20-
Oxopregnanes, C-21 Functionalization.
Abstract: A new D-ring fused steroidal γ-butyrolactone, 3β-hydroxy-5,6-dihydro-17β-methoxypregnan-
21,16α-carbalactone from abundant 20-oxopregnane,5,6-dihydro pregnenolone acetate using
the high yield metal mediated C-21 functionalization reaction with MnO2-TMSCl/AcCl-AcOH system
as the key step has been described. Furthermore, the application of this reaction paving a way to
synthesize 3β,21-diacetoxy -16α,17α-epoxy-pregnan-20-one - a potent precursor towards the synthesis
of a series of D-ring fused steroidal γ-butyrolactones has also been illustrated. The work highlights a
convenient approach in constructing a D-ring fused steroidal γ-butyrolactone system from abundant 20-oxosteroids which
might have general applicability in non-steroidal cyclic system.