Combined directed ortho-metalation, remote metalation, and Stille cross-coupling strategies.: Concise stereoselective synthesis of polysubstituted 9H-fluoren-9-ones

The new sequential stercoselective synthesis of diversely substituted 9H-fluoren-9-ones by ortho-lithiation/Bu3SnCl quench of unprotected benzoic acids followed by Stille cross-coupling reaction and remote metalation is reported. (C) 2008 Elsevier Ltd. All rights reserved.