Enantioselective synthesis of α-sulfenylated ketones and aldehydes via α-thiolation of metalated SAMP/RAMP hydrazones

Article abstract of DOI:10.1016/S0040-4020(98)00481-5

Asymmetric α-sulfenylation of lithiated SAMP/RAMP hydrazones (S)-2 with disulfides afforded α-thiolated hydrazones (S,R)-3 in good yields (48-87%) and high diastereomeric excesses (9196%). Subsequent oxidative cleavage or acidic hydrolysis of the hydrazones furnished α-thiolated ketones (R)-4a-d with high enantiomeric excesses (87→96%). α-Sulfenylated aldehydes (R)-8a- d were prepared by a similar reaction sequence with 45-93% ee.