The reaction of secondary α-amino acids with carbonyl compounds. Properties of the intermediate azomethine ylides. Oxazolidine formation versus 1.4-prototropy.

Azomethine ylides from the reaction of 4

Azomethine ylides from the reaction of 4-(dicyanomethylene)-3-methyl-1-phenyl-2-pyrazoline-5-one with α-amino acids and their esters

✍ Metwally, Saoud A. M. ;Aly, Moustafa F. ;Abd-Alla, Mohamed A. ;Atta, Ferial M. ; 📂 Article 📅 1991 🏛 John Wiley and Sons 🌐 English ⚖ 255 KB 👁 1 views

## Abstract 4‐(Dicyanomethylene)‐3‐methyl‐1‐phenyl‐2‐pyrazoline‐5‐one (1) readily reacts with α‐amino acids and their esters by Michael addition and subsequent elimination of HCN to the adducts 2a–k. One of these, 2i (obtained from methyl glycinate), adds stereoselectively to __N__‐phenylmaleimide