(3S,4S)-3-<(R)-1-tetrahydropyran-2-yloxyethyl>-4-<(S)-1-(p-nitrophenoxycarbonyloxy)ethyl>-2-azetidinone
(3S,4S)-4-<(S)-1-benzyloxyethyl>-3-<(R)-1-tetrahydropyran-2-yloxyethyl>-2-azetidinone
(3S,4S)-4-<(S)-1-(N-methoxycarbamoyloxy)ethyl>-3-<(R)-1-tetrahydropyran-2-yloxyethyl>-2-azetidinone
(3S,4S)-3-<(R)-1-tetrahydropyran-2-yloxyethyl>-4-<(S)-1-hydroxyethyl>-2-azetidinone
(3S,4S)-4-<(S)-1-benzyloxyethyl>-3-<(R)-1-hydroxyethyl>-2-azetidinone