Enantioselective synthesis of phospholanes using chiral lithium amide desymmetrisation

The enantioselective deprotonation of 1,2,5-triphenylphospholane oxide with a chiral base, followed by electrophilic quenching, gives a range of chiral products in good yield and in ca. 85% ee. The absolute and relative configuration of two of the products was determined by X-ray crystallography. A number of the chiral phospholane oxides were subjected to further transformations, in particular reduction to give enantiomerically pure phospholanes.