(S)-cis-2-N,N-di-tert-butyloxycarbonylamino-7-(2-ethyl[1,3]diothiolan-2-yl)hept-5-enoic acid methyl ester

(S)-2-N,N-di-tert-butyloxycarbonylamino-7-(2-ethyl[1,3]diothiolan-2-yl)heptanoic acid methyl ester

(S)-2-(dibenzylamino)-6-oxohexanoic acid benzyl ester

(E)-(S)-2-Dibenzylamino-6-methoxy-hex-5-enoic acid benzyl ester

(S)-2-tert-butoxycarbonylamino-7-(2-ethyl[1,3]dithiolan-2-yl)heptanoic acid