The synthesis of keto ester 15 related to the limonoid antifeedant azadiradione has been achieved in nine steps starting from hydroxy ester 1. The key steps involve a Nazarov cyclization 6-->10 and a stereoselective epoxy ketone rearrangement to enone 13-->15. (C) 1997 Elsevier Science Ltd.
The synthesis of keto ester 15 related to the limonoid antifeedant azadiradione has been achieved in nine steps starting from hydroxy ester 1. The key steps involve a Nazarov cyclization 6-->10 and a stereoselective epoxy ketone rearrangement to enone 13-->15. (C) 1997 Elsevier Science Ltd.