Diastereo- and enantioselective synthesis of α,α'-disubstituted, C2-symmetric ketones using the SAMP-/RAMP-hydrazone method

Article abstract of DOI:10.1055/s-1991-28405

Starting from simple, symmetric ketones such as, 3-pentanone,1,3-diphenyl-2-propanone and 2,2-dimethyl-1,3-dioxan-5-one, α,α'-bisalkylation of the corresponding SAMP-hydrazones (S)-2 and (S)-8 [(S)-1 -(alkylideneamino)-2-(methoxymethyl)pyrrolidines and (S)-1-(2,2-dimethyl-1,3-dioxan-5-ylideneamino)-2-(methoxymethyl)pyrroli dines, respectively], followed by oxidative cleavage with ozone affords chiral, C₂-symmetric ketones 5 and (S,S)-11 of high diastereo- and enantiomeric purity (de, ee > 98%).