Radical-Based Asymmetric Synthesis:  An Iterative Approach to 1, 3, 5, ... (2n + 1) Polyols

1999-09-04T00:00:00Z (GMT) by Philip Garner James T. Anderson
A conceptually novel approach to 1, 3, 5, ... (2n+ 1) polyols based on iterative stereocontrolled homologation of chiral hydroxyalkyl radicals is reported. Starting from α-keto ester precursors, the general sequence of (1) ketone reduction, (2) auxiliary attachment, (3) saponification, (4) Barton esterification, and (5) radical addition provided the two-carbon homologue in 70−80% overall yield. The simplicity and generality of this iterative strategy for 1, 3, 5, ... (2n+ 1) polyol synthesis suggests an attractive alternative for the preparation of molecules containing this structural motif.