Preetismita Borah, Ashma Begum, Saroj Hazarika and Pritish Chowdhury Pages 566 - 573 ( 8 )
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.
γ-Butyrolactones, D-ring fused Steroidal γ-Butyrolactones, Antitumor Steroids, 5α, 20- Oxopregnanes, C-21 Functionalization.
Natural Products Chemistry Division, CSIR-North East Institute of Science & Technology, Jorhat 785006, India.