@Article{IPB-2193, author = {Voigt, B. and Porzel, A. and Adam, G. and Golsch, D. and Adam, W. and Wagner, C. and Merzweiler, K.}, title = {{Synthesis of 2,24-Diepicastasterone and 3,24-Diepicastasterone as Potential Brassinosteroid Metabolites of the Cockroach Periplaneta americana}}, year = {2002}, pages = {91-102}, journal = {Collect. Czech. Chem. Commun.}, doi = {10.1135/cccc20020091}, volume = {67}, abstract = {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.} }