Studies on chromium (0)-promoted higher-order cycloaddition-based benzannulation. Total synthesis of (+)-estradiol

JH Rigby, NC Warshakoon…

Index: Rigby, James H.; Warshakoon, Namal C.; Payen, Anne J. Journal of the American Chemical Society, 1999 , vol. 121, # 36 p. 8237 - 8245

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Citation Number: 42

Abstract

A benzannulation sequence featuring [6π+ 4π] cycloaddition of (η6-thiepin 1, 1-dioxide) tricarbonylchromium (0) complexes with highly substituted dienes followed by Ramberg- Bäcklund rearrangement has been developed. Enantiomerically pure (+)-estradiol (estra-1, 3, 5 (10)-triene-3, 17β-diol) has been synthesized by employing a higher-order cycloaddition between an appropriately substituted thiepin dioxide chromium (0) complex and a diene ...