FORMATION OF 4-DEOXY-GLYCERO-HEXO-2,3-DIULO-FURANOSE FROM MICROTHECIN

4-Deoxy-glycero-hexo-2,3-diulose was formed from microthecin [2-hydrox y-2-(hydroxymethyl)-2H-pyran-3(6H)-one] in neutral water solutions by a Michael addition. The compound was determined by NMR spectroscopy, M S and polarimetry to be a racemic mixture of D-and L-forms and existin g mainly as two furanosidic C-2 epimers in equilibrium with microtheci n. GC-MS analysis showed that 4-deoxy-glycero-hexo-2,3-diulose and mic rothecin were present in extracts of the red alga Gracilariopsis leman eiformis. (C) 1998 Published by Elsevier Science Ltd. All rights reser ved.