Direct Carbon−Carbon Bond Formation via Reductive Soft Enolization: A Kinetically Controlled syn-Aldol Addition of α-Halo Thioesters and Enolizable Aldehydes
摘要:
The direct addition of enolizable aldehydes and alpha-halo thioesters to produce beta-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 alpha-hydroxy aldehyde derivative is used.