Collect. Czech. Chem. Commun. 2002, 67, 91-102

Synthesis of 2,24-Diepicastasterone and 3,24-Diepicastasterone as Potential Brassinosteroid Metabolites of the Cockroach Periplaneta americana

Brunhilde Voigta,*, Andrea Porzela, Günter Adama, Dieter Golschb, Waldemar Adamb, Christoph Wagnerc and Kurt Merzweilerc

a Abteilung für Naturstoffchemie, Leibniz-Institut für Pflanzenbiochemie, Weinberg 3, 06120 Halle/S., Germany
b Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
c Fachbereich Chemie, Martin-Luther-Universität, Kurt-Mothes-Str. 2, 06120 Halle/S., Germany


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.

Keywords: Steroids; Phytohormones; Ecdysteroids; Oxidations; Brassinosteroids; 2,24-Diepicastasterone; 3,24-Diepicastasterone; Metabolism; Periplaneta americana.

References: 25 live references.