250331-24-9Relevant academic research and scientific papers
Studies on chromium(0)-promoted higher-order cycloaddition-based benzannulation. Total synthesis of (+)-estradiol
Rigby, James H.,Warshakoon, Namal C.,Payen, Anne J.
, p. 8237 - 8245 (1999)
A benzannulation sequence featuring [6π + 4π] cycloaddition of (η6- thiepin 1,1-dioxide)tricarbonylchromium(0) complexes with highly substituted dienes followed by Ramberg-Backlund 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 panner derived from an enantiomerically pure indandione precursor as the key ring construction event. Subsequent Ramberg-Backlund rearrangement of this cycloadduct and routine functional group interchanges afforded the steroid target.
