摘要：

Model compounds ul -1 and lk-1 have been studied to determine both the position of the silicon electrofuge and the relative orientation of the double bonds in the transition structure of the allylmetal-aldehyde condensation. The use of the deuterium label allows an unbiased assessment of the syn versus anti S_E' pathways. The synthesis of configurational proof of model systems ul-1 and lk-1 are discussed as well as the cyclization of the model system. Cyclization of model 1 was found to proceed with high selectivity via an anti S_E' pathway regardless of the proximal/distal ratio for all Lewis acids studied. Reactions promoted by fluoride ion favored the proximal product, but both syn and anti pathways were observed.

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