di-tert-butyl dicarbonate
(S)-2-{[(S)-3-Benzyloxycarbonyl-3-(tetrahydro-pyran-2-yloxy)-propyl]-tert-butoxycarbonyl-amino}-4-hydroxy-butyric acid benzyl ester
(S)-4-[tert-Butoxycarbonyl-((S)-2-oxo-tetrahydro-furan-3-yl)-amino]-2-(tetrahydro-pyran-2-yloxy)-butyric acid benzyl ester
(S)-4-((S)-2-Oxo-tetrahydro-furan-3-ylamino)-2-(tetrahydro-pyran-2-yloxy)-butyric acid benzyl ester
(S)-4-Oxo-2-(tetrahydro-pyran-2-yloxy)-butyric acid benzyl ester