The synthesis of androstane brassinosteroid analogues with α-azido acid ester groups in position 17β

Androstane brassinosteroid analogues with α-azido acid ester groups in position 17β were synthesized from 2α,3α,17β-trihydroxy-5α-androstan-6-one after the protection of the 2α,3α-diols upon treatment with the corresponding α-azido acid and the subsequent deprotection of the diol grouping. Six new castasterone analogues were prepared. The biological activities were evaluated in two bioassays: a rice lamina inclination test and bean second internode bioassays. The activities of the new analogues differ in these two bioassays.