The Efficient and Enantiospecific Total Synthesis of Cyclopenta[
<i>b</i>
]phenanthrenes Structurally‐Related to Neurosteroids
作者:Mingxing Qian、Douglas F. Covey
DOI:10.1002/adsc.201000370
日期:2010.10.9
functionalized at C-3 and C-8 from an optically pure Hajos-Parrish ketone. The key step is a neutral alumina catalyzed Michael addition of a Hajos-Parrish ketone derivative (4) to 1,7-octadien-3-one (2) in 98% yield. This Michael addition product went through Krapcho decarbomethoxylation, aldol condensation, lithiumliquidammoniareduction, Wacker oxidation and acid catalyzed cyclization to form cyclo