Chiral 1,3-cyclobutane amino acids: Syntheses and extended conformations

Article abstract of DOI:10.1016/S0040-4039(97)00200-1

Optically active samples of the N-protected 1,3-cyclobutane amino acids 1 and 2 were prepared from α-pinene. The synthesis of 1 is enantiodivergent insofar as both optical antipodes of the product can be prepared from the same α-pinene enantiomer. Single crystal X-ray diffraction studies of derivatives of 1 reveal these compounds can have extended conformations.