Efficient Organocatalytic Cross-Aldol Reaction between Aliphatic Aldehydes through Their Functional Differentiation

A chemo- and stereoselective asymmetric direct cross-aldol reaction between aliphatic aldehydes and alpha-chloroaldehydes has been developed as a method for the formation of the sole cross-aldol adduct with both enantio- and diastereocontrol, and either anti- or syn-aldol adducts were obtained in good to excellent stereoselectivities by use of proline or a novel axially chiral amino sulfonamide as catalyst.