Investigations of the metabolic conversion of the phytohormone 24-epicastasterone (1) in the cockroach Periplaneta americana (L.) required the synthesis of 2,24-diepicastasterone (4), 3,24-diepicastasterone (7b) and 2-dehydro-3,24-diepicastasterone (9) as reference standards. 2,24-Diepicastasterone (4) was synthesized from 2α,3α-epoxy derivative 2 as well as from the 2β,3β-epoxy-22,23-diol 3 by acid-catalyzed water addition to the epoxy function leading to the desired 2β,3α-trans functionality. 3,24-Diepicastasterone (7b) was prepared by NaBH4-reduction of the 3-oxo derivative 6. Upon deprotection conditions from the ketol acetonides 6 and 8 in both cases 2-dehydro-3,24-diepicastasterone (9) was obtained. The structure of 2,24-diepicastasterone (4) was confirmed by X-ray analysis.
对植物激素24-epicastasterone (
1)在美洲蠊(
Periplaneta americana (L.))中的代谢转化的研究需要合成2,24-diepicastasterone (
4)、3,24-diepicastasterone (
7b)和2-dehydro-3,24-diepicastasterone (
9)作为参考标准。2,24-diepicastasterone (
4)由
2α,3α-环氧衍
生物2和2β,3β-环氧-22,23
-二醇3经酸催化加
水反应制得,得到所需的2β,3α-
trans官能团。3,24-diepicastasterone (
7b)通过NaBH
4还原3-酮衍
生物6制备而成。在去保护酮醇
丙酮酸酯
6和
8的条件下,两种情况都得到2-dehydro-3,24-diepicastasterone (
9)。2,24-diepicastasterone (
4)的结构经过X射线分析得到证实。