Issue 7, 1988

Synthesis of the 14α- and 16α-epimers of bufotalin acetate and 16-deacetylcinobufagin

Abstract

The syntheses of two new bufadienolides with ring-D oxygen substituents in abnormal configurations have been summarised. Sodium borohydride reduction of 3β-acetoxy-16-oxo-14β,15β-epoxy-5β-bufa-20,22-dienolide (3) provided a readily separable (1 : 1) mixture of 16α-deacetylcinobufagin (1a) and its previously known 16β-epimer. Also, 14-epi-bufotalin acetate (2a) was obtained by a sequence in which 14-dehydrobufotalin acetate (7) was epoxidised with m-perchlorobenzoic acid to give the diacetate (5a), selective alkaline hydrolysis of which gave the monoacetate (5b), which was then oxidised with chromium trioxide to give the ketone (8); reduction of (8) with chromium(II) acetate gave the alcohol (9), which was then reduced at the carbonyl to the diol (2b) with Urushibara nickel, and finally acetylated to afford the synthetic objective (2a).

Article information

Article type
Paper

J. Chem. Soc., Perkin Trans. 1, 1988, 2037-2041

Synthesis of the 14α- and 16α-epimers of bufotalin acetate and 16-deacetylcinobufagin

Y. Kamano, G. R. Pettit, M. Inoue, M. Tozawa, C. R. Smith and D. Weisleder, J. Chem. Soc., Perkin Trans. 1, 1988, 2037 DOI: 10.1039/P19880002037

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements