[1,2]-Wittig rearrangement of enantio-defined α- alkoxyalkyllithiums: Stereochemistry at the Li-bearing terminus and mutual recognition of enantiomers during the radical recombination

The [1,2]-Wittig rearrangements of enantio-defined α-benzyloxypropyllithium and its (R)-α-methylbenzyloxy analogs, generated from the enantio-enriched stannanes via Sn / Li exchange, are shown to proceed predominantly with inversion of configuration at the Li-bearing terminus and retention of configuration at the migrating center, and exhibit a significant level of mutual enantiomer recognition in the radical recombination process.