Efficient syntheses of l-ribose and 2-deoxy l-ribose from d-ribose and l-arabinose
摘要:
Interconversion of the ends of D-ribose 2 afforded in 6 steps and 45% overall yield L-ribose 1, from which 2-deoxy L-ribose 12 was easily prepared. In addition, the inexpensive L-arabinose 13 was also converted into 2-deoxy L-ribose 12 via a reductive radical rearrangement of the arabinopyranosyl bromide 14. (C) 1997 Elsevier Science Ltd.
Synthesis of allyl 2-O-(α-l-arabinofuranosyl)-6-O-(α-d-mannopyranosyl)-β-d-mannopyranoside, a unique plant N-glycan motif containing arabinose
作者:Jean-Pierre Utille、Bernard Priem
DOI:10.1016/s0008-6215(00)00185-3
日期:2000.11
The synthesis of the trisaccharide allyl 2-O-(alpha -L-arabinofuranosyl)-6-O-(alpha -D-mannopyranosyl)-beta -D-mannopyranoside is reported. Stereoselective glycosylation at C-6 of a non-protected allyl beta -mannoside with the acetylated alpha -D-mannosyl bromide gave the alpha-(1 --> 6)-disaccharide as the main product and the crystalline 3,6-branched trisaccharide as minor compound. Further glycosylation of the 2,3 diol (1 --> 6) disaccharide with L-arabinofuranosyl bromide furnished a mixture of 3-O- and 2-O-alpha -L-Ara-trisaccharides from which the title compound was isolated. (C) 2000 Elsevier Science Ltd. All rights reserved.