Synthesis of alpha-N-ethylamino acids and their derivatives

A new synthesis of alpha-N-ethylamino acids starting from alpha-amino acids using hexafluoroacetone as protecting and activating agent is described. T he hexafluoroacetone-protected N-ethylamino acid derivatives obtained are a ctivated lactons. Therefore, they can be directly transformed without the n eed of an additional activation step with various nucleophiles into the cor responding carboxylic acid derivatives.