Acyclic asymmetric induction with carboncarbon bond formation

The acyclic asymmetric induction is described which involves heteroconjugate addition of MeLi to α-hydroxy hetero-olefins and concomitant intramolecular silicon-migration to produce α,α-sulfonyl-dianion of the $\text{threo}$ adduct being of utility for the second CC bond formation in one pot. It also contains the first chemical proof of the regiochemical assignment to the hetero-olefins.