Convenient synthesis of α-acylamino aldehydes

The reduction by di-isobutylaluminium hydride of N-blocked amino acid imidazolides gives good yields of α-acylamino aldehydes, the optical purity of which is higher than those previously reported, but a check of one aldehyde prepared showed only 60% optical purity; the chemical shifts at the aldehydo 13C and 1H resonances are reported.