(4S,5S)-5-[(S)-1-(tert-Butyl-dimethyl-silanyloxy)-but-2-ynyl]-4-(4-hydroxy-but-1-ynyl)-oxazolidin-2-one

(4S,5S)-5-Hydroxymethyl-4-[4-(4-methoxy-benzyloxy)-but-1-ynyl]-oxazolidin-2-one

Toluene-4-sulfonic acid 3-[(3aS,6S,6aS)-6-(tert-butyl-dimethyl-silanyloxy)-5-eth-(Z)-ylidene-2-oxo-hexahydro-cyclopentaoxazol-(4Z)-ylidene]-propyl ester

(4S,5S)-5-[(S)-1-(tert-Butyl-dimethyl-silanyloxy)-but-2-ynyl]-4-[4-(4-methoxy-benzyloxy)-but-1-ynyl]-oxazolidin-2-one

Toluene-4-sulfonic acid 4-{(4S,5S)-5-[(S)-1-(tert-butyl-dimethyl-silanyloxy)-but-2-ynyl]-2-oxo-oxazolidin-4-yl}-but-3-ynyl ester