Acetic acid 2,2,4-trimethyl-5-oxo-2,5-dihydro-furan-3-yl ester

rel-(3S,4S)-3-Methyl-3-thiophenoxy-4-<(trimethylsilyl)ethynyl>-2-azetidinone

rel-(3R,4S)-3-Methyl-3-thiophenoxy-4-<(trimethylsilyl)ethynyl>-2-azetidinone

Acetic acid (3S,4S)-2,2-diethyl-4-methyl-5-oxo-4-phenylsulfanyl-tetrahydro-furan-3-yl ester

Acetic acid (3R,4S)-2,2-diethyl-4-methyl-5-oxo-4-phenylsulfanyl-tetrahydro-furan-3-yl ester