Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Main Authors: Vladimir N. Zhabinskii, Darya A. Osiyuk, Yuri V. Ermolovich, Natalia M. Chaschina, Tatsiana S. Dalidovich, Miroslav Strnad, Vladimir A. Khripach
• Format: Article
• Language: English
• Published: Beilstein-Institut 2017-11-01
• Series: Beilstein Journal of Organic Chemistry
• Subjects: biosynthetic precursors; brassinosteroids; diols; epibrassinolide; epicastasterone; metabolites
• Online Access: https://doi.org/10.3762/bjoc.13.229
• ISSN: 1860-5397

Herein, we present a new strategy for the preparation of a broad range of brassinosteroid biosynthetic precursors/metabolites differing by the ring A fragment. The protocol is based on the use of readily available phytohormones of this class bearing a 2α,3α-diol moiety (epibrassinolide or epicastasterone) as starting materials. The required functionalities (Δ2-, 2α,3α- and 2β,3β-epoxy-, 2α,3β-, 2β,3α-, and 2β,3β-dihydroxy-, 3-keto-, 3α- and 3β-hydroxy-, 2α-hydroxy-3-keto-) were synthesized from 2α,3α-diols in a few simple steps (Corey–Winter reaction, epoxidation, oxidation, hydride reduction, etc.).