- Deoxyiminoalditols from aldonolactones - V. Preparation of the four stereoisomers of 1,5-dideoxy-1,5-iminopentitols. Evaluation of these iminopentitols and three 1,5-dideoxy-1,5-iminoheptitols as glycosidase inhibitors
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The four stereoisomeric 1,5-dideoxy-1,5-iminopentitols with D-arabino - (D-lyxo-) (3), ribo- (9), L-lyxo- (L-arabino-) (13) and xylo- (18) configurations were synthesized. The corresponding aldonolactones (1, 7 and 11) or aldonic acid ester (15b) having a leaving group at C-5 gave by reaction with aqueous ammonia, the 5-amino-5-deoxy-1,5-lactams, 2, 8, 12 and 17, respectively. Reduction of the lactam function using sodium borohydride/acetic or trifluoroacetic acid, or borane dimethyl sulfide complex yielded the iminopentitols. The compounds 3, 9, 13 and 18, together with the three 1,5-dideoxy-1,5-iminoheptitols 19, 20 and 21 were tested for inhibition of the glycosidase activities present in an extract from human liver. Compound 18 was a potent and 19 a moderately good inhibitor of β-glucosidase. Compound 3 together with 19, 20 and 21, all having D-arabino-configuration at the hydroxy-substituted carbon atoms, were good inhibitors of α-L-fucosidase.
- Godskesen, Michael,Lundt, Inge,Madsen, Robert,Winchester, Bryan
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p. 1857 - 1865
(2007/10/03)
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- α- or β-Amino Polyhydroxy Acids from the Reaction of Bromodeoxyaldonolactones with Liquid Ammonia
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Reaction of 2-bromo-2-deoxy-L-threono- (1) or -D-xylono-1,4-lactone (4) with liquid ammonia, gives 3-amino-3-deoxy-D-threonic- (3a) and -D-arabinonic acid (6a), respectively.The latter (6a) could be converted into the hydrochloride of 3-amino-3-deoxy-D-arabinono-1,4-lactone (7).The 2,5-dibromo-2,5-dideoxy-D-xylono-1,4-lactone (13) yielded 2,5-diamino-2,5-dideoxy-D-xylono-1,5-lactam (21) with liquid ammonia.This was also obtained from 2,5-dibromo-2,5-dideoxy-D-lyxonolactone (14) under similar conditions.In both reactions varying amounts of the C-2 epimeric 2,5-diamino-2,5-dideoxy-D-lyxono-1,5-lactam (20), were formed, owing to base-catalysed epimerisation.By monitoring the reaction of 2-bromo-2-deoxy- as well as of 2,5-dibromo-2,5-dideoxyaldonolactones with aqueous ammonia by 13C NMR spectroscopy, it was shown that 2,3-epoxy carboxamides were intermediates.The 2,3-epoxy function in L-erythro-(2) and D-lyxo-(5) epoxycarboxamides were stable in aqueous ammonia, while the cyclic 2,3-epoxy-D-lyxono-lactam (17) opened at C-2 within 20 h to give 21.
- Bols, Mikael,Lundt, Inge
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p. 280 - 284
(2007/10/02)
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