Abstract
Optically pure tert -butanesulfinyl aldimines 1 were prepared by direct condensation of chiral tert -butanesulfinamide 3 with aldehydes 2 in high yields in the presence of KHSO4 . The main advantage of KHSO4 is that it is applicable to the condensation reactions of a variety of aldehydes, including electron deficient and electron rich (hetereo)aromatic aldehydes, as well as aliphatic aldehydes.
Key words
tert -butanesulfinamide - aldehyde -
tert -butanesulfinyl aldimines - potassium hydrogen sulfate - condensation
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8 General procedure: (S )-tert -Butanesulfinamide (1 mmol) was stirred with benzaldehyde (2 mmol) in toluene (10 mL) in the presence of KHSO4 (2 equiv) for 24 h at 45 °C. KHSO4 was then removed by filtration. The filtrate was concentrated to dryness. The residue was purified by flash chromato-graphy to afford (S )-tert -butanesulfinyl aldimine (1a ) as a colorless liquid. [α]D
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