Highly flexible synthetic routes to functionalized phospholanes from carbohydrates

Highly functionalized phospholanes 15, 17, and 26 and the corresponding dia stereomers in which the configurations of the phospholane carbon-2 and carb on-5 are inverted can be readily prepared from D-mannitol by displacement o f the appropriate dimesylate or cyclic sulfate with dilithiumphosphide reag ents. The diols from which these ligands are prepared can also be converted into diarylphosphinite ligands. A route to related monophosphines bearing hemilabile tert-butylthio groups is also described. Complexes of these liga nds and of related deprotected derivatives are potentially useful for enant ioselective catalysis in organic and aqueous media.