title: A new synthesis of brassinosteroids with a cholestane framework based on a highly functionalized starting material.
abstract: A new route to the synthesis of minor brassinosteroids with a cholestane framework (28-norcastasterone and 28-norbrassinolide) has been proposed. It makes use of commercially available 24-epicastasterone as a starting material. In addition, [26,26,26-(2)H3]-28-norcastasterone and [26,26,26-(2)H3]-28-norbrassinolide have been prepared as tools for analytical applications. The key steps were regioselective manipulations of functional groups in 24-epicastasterone, oxidative cleavage of 22,23-diol group and Claisen rearrangement.
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Kuprevich str., 5/2, 220141 Minsk, Belarus.
authors.forename: Irina D
authors.initials: ID
authors.lastname: Alshakova
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Kuprevich str., 5/2, 220141 Minsk, Belarus.
authors.forename: Yuri V
authors.initials: YV
authors.lastname: Ermolovich
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Kuprevich str., 5/2, 220141 Minsk, Belarus.
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Zhabinskii
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Kuprevich str., 5/2, 220141 Minsk, Belarus. Electronic address: khripach@iboch.bas-net.by.
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Khripach
mesh_terms: D060406:Brassinosteroids / Q000138:chemical synthesis* / Q000737:chemistry; D002776:Cholestanes / Q000737:chemistry*; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D060406:Brassinosteroids; D002776:Cholestanes
keywords: 24-Epicastasterone; 28-Norbrassinolide; Boric acid ester; Brassinosteroids; Claisen rearrangement; Deuterated analogues