benzyl (1S,5R)-6-(hydroxymethyl)-3-azabicyclo[3.1.0]hexane-3-carboxylate

(1R,5S)-3-phenylmethoxycarbonyl-3-azabicyclo[3.1.0]hexane-6-carboxylic acid

(1α,5α,6α)-6-tert-butoxycarbonylamino-3-aza-bicyclo[3.1.0]hexane-3-carboxylic acid benzyl ester