(3R,2'S) N-(Benzyl)-3-(3'-acetoxy-2'-tert-butyldimethylsilylpropyl)-isoxazolidin-5-one

1-benzyl 5-methyl (R)-3-tert-butoxycarbonylaminoglutarate

(R)-3-Amino-pentanedioic acid benzyl ester methyl ester

(S)-N-benzyl-4-2'-tetrahydropyranoxymethyl-2-azetidinone

ethyl (S)-3-benzylamino-4-2'-tetrahydropyranoxybutyrate