Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Communication | Special issue | Vol 28, No. 1, 1989, pp.59-62
Published online, 1st January, 1970
DOI: 10.3987/COM-88-S23
Stereocontrolled Synthesis of the Withanolide D Side Chain from 20-Oxosteroid

Tetsuji Kametani, Masayoshi Tsubuki, and Toshio Honda*

*Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan

Abstract

A new procedure for the construction of the withanolide D side chain starting from 20-oxopregnane is described. The key reactions are stereochemical control of C-20 and C-22 positions involving stereoselective hydrogenation of the enone 4, and an efficient transformation of the resulting γ-lactone 5 into the δ-lactone 8. Successful isomerization of the olefin 12 using RhCl3 is also reported.