Abstract Two hitherto unknown brassinolide analogues, (22 R ,23 R )-2α,3α,22,23-tetrahydroxy- B -homo-7-oxa-24-nor-5α-cholestan-6-one ( 9b ) and (22 R ,23 R )-2α,3α,22,23-tetrahydroxy-24-nor-5α-cholestan-6-one ( 8a ), were stereoselectively synthesized. In both the Raphanus and rice-lamina inclination tests, 9b exhibited almost the same activity as brassinolide ( 1 ) and 8a also showed ca 10–50% of
摘要 两种迄今为止未知的芸苔素
内酯类似物,(22 R ,23 R )-
2α,3α,22,23-四羟基-B-homo-7-oxa-24-nor-5α-cholestan-6-one ( 9b ) 和 (22 R ,23 R )-
2α,3α,22,23-tetrahydroxy-24-nor-5α-cholestan-6-one ( 8a ) 是立体选择性合成的。在萝卜和
水稻叶片倾斜试验中,9b 表现出与
芸苔素内酯几乎相同的活性 (1),8a 也表现出大约 1 的 10-50% 的活性。