Asymmetric alkenylation of chiral and prochiral aldehydes catalysed by chiral or achiral amino alcohols: catalytic diastereoselective synthesis of protected erythro-sphingosine and enantioselective synthesis of chiral diallyl alcohols

Protected D-erythro-(2S,3R)-sphingosine was preferentially obtained by diastereoselective pentadec-1-enylation of tert-butyl (S)-4-formyl-2,2-dimethyloxazolidine-3-carboxylate with pentadec-1-enyl(ethyl)zinc using either (R)-diphenyl(1-methylpyrrolidin-2-yl)methanol (DPMPM) as a Chiral catalyst or 2-(dibutylamino)ethanol as an achiral catalyst. Enantioselective alkenylation of α,β-unsaturated aldehydes using (S)-DPMPM as a Chiral catalyst affords Chiral diallyl alcohols with good enantiomeric excesses.