Total Synthesis with a Chirogenic Opening Move Demonstrated on Steroids with Estrane or 18a??Homoestrane Skeleton

…, GT Dambacher, JW Bats, G Zimmermann…

Index: Quinkert; Del Grosso; Doring; Schenkel; Bauch; Dambacher; Bats; Zimmermann; Durner Helvetica Chimica Acta, 1995 , vol. 78, # 5 p. 1345 - 1391

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Citation Number: 55

Abstract

Abstract A concept of first choice for the synthesis of the title compounds had been proposed by Dane in the late 1930s. It was soon turned down, because the opening move–a chirogenic Diels-Alder reaction–did not work. With Lewis acids as mediators, however, a successful start has been achieved now. With Ti complexes of chelating ligands (Seebach's TADDOLs (= α, α, α′, α′-tetraaryl-1, 3-dioxolane-4, 5-dimethanols)), enantioselective ...