Popis: |
Three O -isopropylidene group-protected pentose aldehydes (methyl 2,3- O -isopropylidene-β- d - ribo -pentodialdo-1,4-furanoside ( 1 ), methyl 2,3- O -isopropylidene-α- d - lyxo -pentodialdo-1,4-furanoside ( 2 ), and 3- O -benzyl-1,2- O -isopropylidene-α- d - xylo -pentodialdo-1,4-furanose ( 3 )) were treated at −30 °C with lithium diisopropylamide (LDA) and the mixtures obtained were reduced with LiAlH 4 . The products, obtained in moderate yields, proved that deacetonation occurred followed by aldol reactions between aldehydes 1 – 3 and acetone. |