Access to Enantiopure 5-, 7-, and 5,7-Substituted cis-Decahydroquinolines: Enantioselective Synthesis of (-)-Cermizine B

摘要

Stereoconvergent cyclocondensation reactions of (R) or (S)-phenylglycinol with appropriately substituted cyclo- hexanone-based delta-keto esters are the key steps:of short synthetic routes to enantiopure 5- 7-, and 5,7-substituted cis-decahydroquinolines. The factors governing the stereoselectivity of the cyclocondensation are discussed. The potential of the methodology is illustrated by a protecting-group-free synthesis of the phlegmarine-type Lycopodium alkaloid (-)-cermizine B.