Stereoselection in the Prins-Pinacol Synthesis of Acyltetrahydrofurans
摘要:
Depending upon the nature of the alkene and allylic substituents, acid-promoted rearrangements of acetals derived from anti allylic diols give 12 or stereoisomeric acyltetrahydrofurans 13. Stereoelectronic effects of the allylic substituents and the extent of bonding in the Prins cyclization transition state are central features of a proposed new model for predicting stereoselection in the Prins-pinacol synthesis of acyltetrahydrofurans.
Stereocontrolled preparation of tetrahydrofurans from acid-promoted rearrangements of allylic acetals
作者:Mark H. Hopkins、Larry E. Overman、Gilbert M. Rishton
DOI:10.1021/ja00014a030
日期:1991.7
tetrahydrofurans from readily available allylic diol and carbonyl components is reported. This synthesis is highly stereocontrolled and allows carbon side chains to be incorporated at each carbon. Enantiomerically pure tetrahydrofurans are readily prepared from chiral, nonracemic allylic diol precursors. The asymmetric synthesis of (+)-muscarine tosylate from the lactate-derived allylic diol 6a demonstrates that