tert-Butyl (3R,5S)-6-hydroxy-3,5-O-isopropylidene-3,5-dihydroxyhexanoate2,4-Dideoxy-3,5-O-(1-methylethylidene)-D-erythro-hexonic Acid 1,1-Dimethylethyl Ester(4R,6S)-6-Hydroxymethyl-2,2-dimethyl-1,3-dioxane-4-acetic Acid 1,1-Dimethylethyl Ester2-[(4R,6S)-6-(Hydroxymethyl)-2,2-dimethyl-1,3-dioxan-4-yl]acetic Acid tert-Butyl Ester