Optically active allylic tin reagent as an enantio-divergent synthon of isoprenoids via remote and divergent asymmetric induction

Abstract

( S)-2-(1-Hydroxymethyl)allytin ( 1a) can be prepared in high enantiomeric purity. When its methylated and acetylated derivatives are allowed to add to aldehydes with the help of i-PrOTiCl 3 and SnCl 4, syn- and anti- homoallylic alcohols are stereoselectively obtained, respectively, via 1,4-asymmetric induction. These reactions are applied to the synthesis of the both enantiomers of a pheromone constituent, ipsenol, from a single enantiomer of 1a.