Application of the chiral acyl anion equivalent, trans-1,3-dithiane 1,3-dioxide, to an asymmetric synthesis of (R)-salbutamol

An enantioselective synthesis of (R)-salbutamol has been carried out using the chiral, C-2\ symmetric acyl anion equivalent, (1-R,3R)-1,3-dithiane 1,3-dioxide, which undergoes addition to an aromatic aldehyde with very high stereocontrol at 0 degreesC. Pummerer reaction and work-up with lithium ethanethiolate generated the alpha-hydroxy thiolester in high yield and further transformations led to the target compound with high enantiomeric excess.