102389-90-2

Formaldehyde reacts with α-amino acids and electron deficient alkenes to produce pyrrolidines.Azomethine ylides involved as intermediates in these reactions have been generated from isolated oxazolidin-5-ones which can be considered as the direct precursors of these ylides.

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 isolated.Some synthetic equivalents of parent azomethine ylide, methaniminium methylide, are accessible by this route.

Decarboxylative condensation of glycine or N-substituted glycines with a variety of carbonyl compounds such as formaldehyde, aromatic aldehyde, or ketones is a convenient and general route to parent methaniminium and its 1-mono- and 1,1-disubstituted derivatives with or without an N-substituent.

Formaldehyde and α-amino acids such as sarcosine and glycine react with alkenes to give N-Me and N-H pyrrolidines via in situ generated azomethine-ylides.