Ecdysteroids. Selective Protections and Synthesis of Potential Tools for Biochemical Studies

Sa？etak B-Ecdysone and cyasterone bave been transformed into the ecdysterone analogue 4, wbich carries a [3-(p-hydroxyphenyl).-propoxylj- group at the end of the side chain. This derivative should be useful for various biochemical investigations (I-labelling, affinity chromatography), since it exhibits a marked ecdysterone-like activity in two independent biological tests. The synthetic scheme makes use of highly selective protections of the hydroxyl groups of phytoecdysteroids