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:

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

Communication | Special issue | Vol 15, No. 2, 1981, pp.823-834
Published online, 1st January, 1970
DOI: 10.3987/S-1981-02-0823
Synethetic Studies of Withanolides. Part 3. Some Approaches for the Side-Chain Lactone Synthesis by Means of γ-Coupling of Lithium Dienolates with the Steroidal 22-Aldehydes

Masaji Ishiguro, Masao Hirayama, Hiromitsu Saito, Akira Kajikawa, and Nobuo Ikekawa*

*Faculty of Engineering, Tokyo Institute of Technology, 2-12-1,Oh-Okayama, Meguro-ku, Tokyo 152-8552, Japan


γ-Coupling of the lithium dienolates 5a-d with the steroidal 22-aldehydes 1-4 was investigated. Condensation of 5a with the (20R)-20-methoxymethyloxy-22-al 4 followed by lactonization gave the (20R,22R)-20-hydroxy-δ-lactone 13 which had the identical structure with withanolide D side-chain moiety, while the reaction of 5a with the 20-deoxy-22-al 1 gave the 22S-δ-lactone 6 which had the opposite stereochemistry at the 22-position to that of deoxywithaferin A. Attempts to invert the 22S-compounds 6 and 11 were unsuccessful. Lactonization of the 5,22,24-trienoic acid 14 gave predominantly the unsaturated γ-lactones.