In this paper we report the development of a stereoselective IMDA approach to the phytotoxic polyketides (+/-)-solanapyrones A and B. The stereoselectivity of the key IMDA cycloaddition was optimized by investigating a range of 2,8,10-dodecatrienoic acid derivatives. This established that use of the Weinreb amide led to the desired exo-selectivity and also facilitated construction of the pyrone moiety. A novel approach to the installation of the C-3 formyl group in solanapyrone A is also described. (C) 2003 Elsevier Science Ltd. All rights reserved.
In this paper we report the development of a stereoselective IMDA approach to the phytotoxic polyketides (+/-)-solanapyrones A and B. The stereoselectivity of the key IMDA cycloaddition was optimized by investigating a range of 2,8,10-dodecatrienoic acid derivatives. This established that use of the Weinreb amide led to the desired exo-selectivity and also facilitated construction of the pyrone moiety. A novel approach to the installation of the C-3 formyl group in solanapyrone A is also described. (C) 2003 Elsevier Science Ltd. All rights reserved.