Synthesis of long-chain monosaccharides via the coupling of three ‘normal’ sugar units via Wittig type methodology: unusual removal of the benzyl group under basic conditions
摘要:
The reaction of diacetonogalactose phosphonate 6 with 2,3:4,5-di-O-isopropylidene-D-arabinose (7) afforded C-12-higher sugar enone with an E-geometry across the double bond, which was converted into the fully protected C-11-aldehyde 16. This compound was very unreactive and resistant toward the Wittig type and Tebbe reagents, but under PTC conditions, underwent a reaction with stabilized sugar phosphonate to afford C-18-enone 17. Very surprisingly unusual removal of the benzyl blocks under these conditions was observed. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of long-chain monosaccharides via the coupling of three ‘normal’ sugar units via Wittig type methodology: unusual removal of the benzyl group under basic conditions
摘要:
The reaction of diacetonogalactose phosphonate 6 with 2,3:4,5-di-O-isopropylidene-D-arabinose (7) afforded C-12-higher sugar enone with an E-geometry across the double bond, which was converted into the fully protected C-11-aldehyde 16. This compound was very unreactive and resistant toward the Wittig type and Tebbe reagents, but under PTC conditions, underwent a reaction with stabilized sugar phosphonate to afford C-18-enone 17. Very surprisingly unusual removal of the benzyl blocks under these conditions was observed. (C) 2011 Elsevier Ltd. All rights reserved.