isopropyl (2S,3R,4S,6R)-7-t-butoxycarbonyl-2,3-bis(t-butyldimethylsilyloxy)-4,6-dihydroxyheptanoate

isopropyl (2S,3R,4S,6R)-7-t-butpxycarbonyl-2,3-bis(t-butyldimethylsilyloxy)-4,6-isopropylidenedioxyheptanoate

isopropyl (2S,3S,6R)-7-t-butoxycarbonyl-2,3-bis(t-butyldimethylsilyloxy)-6-hydroxy-4-oxoheptanoate

isopropyl (2S,3S)-7-t-butoxycarbonyl-2,3-bis(t-butyldimethylsilyloxy)-4,6-dioxoheptanoate

(3S,5R)-tert-butyl 3,5-dihydroxy-5-((2S,3S)-3-(trimethylsilyl)oxiran-2-yl)pentanoate