Direct carbon-carbon bond formation via reductive soft enolization: a kinetically controlled syn-aldol addition of α-halo thioesters and enolizable aldehydes. 
The direct addition of enolizable aldehydes and α-halo thioesters to produce β-hydroxy thioesters enabled by reductive soft enolization is reported.  The transformation is operationally simple and efficient and has the unusual feature of giving high syn-selectivity, which is the opposite of that produced for (thio)esters under conventional conditions.  Moreover, excellent diastereoselectivity results when a chiral nonracemic α-hydroxy aldehyde derivative is used.