The stereochemistry of (3R,2'S)-2'-N-dibenzylamino-1,2:5,6-di-O-isopropylidene-alpha-D-allofuranose-3-spiro-3'-propano-3-lactone, C28H33NO7, has been established, The three five-membered rings adopt envelope conformations, The spiropropiolactone ring is practically planar.
Diastereoselective synthesis of glycosyl-α-aminoacids
摘要:
Asymmetric synthesis of various glycosyl-alpha-aminoacids is described. The approach involves the diastereoselective condensation of glycine enolates on the carbonyl in position 3 of the suitably protected alpha-D-ribohexafuranos-3-ulose. (C) 1997 Elsevier Science Ltd.