Enantiodivergent synthesis of cyclobutyl-(Z)-α,β-dehydro-α-amino acid derivatives from (-)-cis-pinononic acid

The two enantiomers of the title dehydroamino acids (DHAAs) have been synthesized through respective Wadsworth-Emmons condensations of a suitable phosphonate with enantiomeric cyclobutyl aldehydes. These compounds, in turn, were prepared by selective manipulation of the functional groups starting from (-)-cis-pinononic acid as the common chiral precursor. The CD spectra of the prepared DHAAs are described. These products are suitable for the stereocontrolled synthesis of diferent types of saturated cyclobutyl amino acids and their derivatives. © 2003 Elsevier Science Ltd. All rights reserved.