TY - JOUR A1 - Zhabinskii, Vladimir N. A1 - Osiyuk, Darya A. A1 - Ermolovich, Yuri V. A1 - Chaschina, Natalia M. A1 - Dalidovich, Tatsiana S. A1 - Strnad, Miroslav A1 - Khripach, Vladimir A. T1 - Synthesis of ergostane-type brassinosteroids with modifications in ring A JF - Beilstein Journal of Organic Chemistry PY - 2017/// VL - 13 SP - 2326 EP - 2331 SN - 1860-5397 DO - 10.3762/bjoc.13.229 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.13.229 KW - biosynthetic precursors KW - brassinosteroids KW - diols KW - epibrassinolide KW - epicastasterone KW - metabolites N2 - 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.). ER -