Efficient and stereoselective installation of isoquinoline: formal total synthesis of cortistatin A

The highly stereoselective attachment of isoquinoline onto the steroidal framework of cortistatin A has been achieved. Our strategy features a Ce-mediated nucleophilic addition of an isoquinoline unit to the sterically congested ketone followed by formation of the phenyl thiocarbamate, and Subsequent stereoselective radical reduction. The new method results in a formal total synthesis of cortistatin A. (C) 2009 Elsevier Ltd. All rights reserved.