A new synthesis of brassino steroids: Plant growth promoting steroids

(22R,23R)- and (22S,23S)-2α,3α,22,23-Tetrahydroxy-B-homo-7-oxa- 5α-ergostan-6-one, two physiologically active brassino steroids, have been synthesized via key intermediate brassicasterol obtained in a very simple way by reduction with lithium dissolved in ethylamine of the 1,4-cycloadduct of ergosterol and 4-phenyl-1,2,4-triazoline-3,5-dione.