Abstract
L-α-Dimethylamino-ε-caprolactam, a seven-membered cyclic amide, was examined as catalyst for the asymmetric addition of hydrogen cyanide to aldehyde to form cyanohydrin. Optical yield of 5-30% was obtained when aliphatic aldehydes were used as substrate. For example, when isobutyraldehyde was used, optical yield of 26.3% was obtained. By using cyclo (L-Phe-L-His) or L-α-dimethylamino-ε-caprolactam as catalyst, the first example of asymmetric transcyanohydrination between an aldehyde and acetone cyanohydrin was achieved. With isobutyraldehyde as substrate and cyclo(L-Phe-L-His) as catalyst, high optical yield of 62.7 % was obtained.
