AMINO ACID APPROACH AS A GENERAL ROUTE TO NONSTABILIZED AZOMETHINE YLIDES. FACILE GENERATION OF PARENT METHANIMINIUM METHYLIDE AND ITS 1-MONO- AND 1,1-DISUBSTITUTED DERIVATIVES
condensation of glycine or N-substituted glycines with a variety of carbonyl compounds such as formaldehyde, aromatic aldehyde, or ketones is a convenient and generalroute to parent methaniminium methylide and its 1-mono- and 1,1-disubstituted derivatives with or without an N-substituent.
Simple Generation of Nonstabilized Azomethine Ylides through Decarboxylative Condensation of α-Amino Acids with Carbonyl Compounds via 5-Oxazolidinone Intermediates
Heating α-amino acids with a variety of carbonyl compounds generates N-unsubstituted or N-substituted azomethine ylides of nonstabilized types through the elimination of water and carbon dioxide. The ylides are captured by olefinic, acetylenic, and carbonyl dipolarophiles producing pyrrolidines, pyrrolines, and oxazolidines. The reaction involves intermediary 5-oxazolidinones which can be sometimes