1-De-oxy-1-fluoro-l-galactitol.

The crystal structure unequivocally confirms the relative stereochemistry of the title compound, C(6)H(13)FO(5) [6-de-oxy-6-fluoro-d-galactitol or (2S,3R,4R,5S)-6-fluoro-hexane-1,2,3,4,5-penta-ol]. The absolute stereochemistry was determined from the use of d-galactose as the starting material. In the crystal, the molecules are linked by O-H⋯O and O-H⋯F hydrogen bonds, forming a three-dimensional network with each mol-ecule acting as a donor and acceptor for five hydrogen bonds

2-deoxy-L-ribose from an L-arabinono-1,5-lactone

A practical synthesis of 2-deoxy-L-ribose from L-arabinose depends on the efficient reduction by iodide of a triflate α to a lactone. The X-ray crystal structure of 3,4-O-isopropylidene-L-arabinono-1,5-lactone is reported. © 2002 Published by Elsevier Science Ltd

Large scale synthesis of the acetonides of L-glucuronolactone and of L-glucose: easy access to L-sugar chirons

1,2-O-Isopropylidene-α-l-glucurono-3,6-lactone may be synthesized on a 100-200 g scale from cheaply available d-glucoheptonolactone in an overall yield of 94% in four steps via l-glucuronolactone. Subsequent elaboration to l-glucose, diacetone-l-glucose (1,2:5,6-di-O-isopropylidene-α-l-glucofuranose), and monoacetone-l-glucose (1,2-O-isopropylidene-α-l-glucofuranose) allows easy access to a range of l-sugar chirons. © 2009 Elsevier Ltd. All rights reserved

Green aldose isomerisation: 2-C-methyl-1,4-lactones from the reaction of Amadori ketoses with calcium hydroxide

Saccharinic acids, branched 2-C-methyl-aldonic acids, may be accessed via a green procedure from aldoses by sequential conversion to an Amadori ketose and treatment with calcium hydroxide; d-galactose and d-glucose are converted to 2-C-methyl-d-lyxono-1,4-lactone (with a small amount of 2-C-methyl-d-xylono-1,4-lactone) and 2-C-methyl-d-ribono-1,4-lactone. Inversion of configuration at C-4 of the branched lactones allows access to 2-C-methyl-l-ribono-1,4-lactone and 2-C-methyl-l-lyxono-1,4-lactone, respectively. d-Xylose affords 2-C-methyl-d-threono-1,4-lactone and 2-C-methyl-d-erythrono-1,4-lactone, whereas l-arabinose, under similar conditions, gave the enantiomers 2-C-methyl-l-threono-1,4-lactone and 2-C-methyl-l-erythrono-1,4-lactone. © 2006

2-O-(4,4 '-dimethylbenzhydryl)-L-erythronolactone

The high regioselectivity of the SnCl2-catalyzed reaction of diaryl-diazo-methanes with vicinal diols was demonstrated by the reaction of diazo-[bis-(4-methyl-phen-yl)]methane with l-erythronolactone. The major product was unequivocally established by X-ray crystallographic analysis to be the title compound, C19H20O4. The absolute configuration was determined by the use of l-erythronolactone as the starting material. The crystal structure contains alternating O - H⋯O hydrogen-bonded chains of mol-ecules lying perpendicular to the bc plane. © International Union of Crystallography 2007

Looking glass inhibitors: scalable syntheses of DNJ, DMDP, and (3R)-3-hydroxy-L-bulgecinine from D-glucuronolactone and of L-DNJ, L-DMDP, and (3S)-3-hydroxy-D-bulgecinine from L-glucuronolactone. DMDP inhibits beta-glucosidases and beta-galactosidases whereas L-DMDP is a potent and specific inhibitor of alpha-glucosidases

A convenient large-scale synthesis of 1-deoxynojirimyin (DNJ) from d-glucuronolactone involves introduction of azide at C-5 with retention of configuration to give 5-azido-5-deoxy-1,2-O-isopropylidene-α-d-glucofuranose as a key intermediate in an overall yield of up to 72%; the same intermediate can be transformed into DMDP [(2R,3R,4R,5R)-2,5-bis(hydroxymethyl)pyrrolidine-3,4-diol] and (3R)-3-hydroxy-l-bulgecinine [(2S,3R,4R,5R)-3,4-dihydroxy-5-hydroxymethyl-l-proline]. l-Glucuronolactone, a readily available l-sugar chiron, may similarly be used to access the enantiomers l-DNJ, l-DMDP, and (3S)-3-hydroxy-d-bulgecinine. A comparison of glycosidase inhibition by DMDP (an inhibitor of β-glucosidases and β-galactosidases) and l-DMDP (a potent and specific α-glucosidase inhibitor) with the corresponding enantiomeric hydroxybulgecinines is reported; DMDP and (3R)-3-hydroxy-l-bulgecinine show weak inhibition of glycogen phosphorylase. © 2010 Elsevier Ltd. All rights reserved

Doubly carbon-branched pentoses: synthesis of both enantiomers of 2.4-di-C-methyl arabinose and 2-deoxy-2,4-di-C-methyl arabinose using only acetonide protection

An acetonide is the only protecting group used in the synthesis of both the enantiomers of 2,4-di-C-methyl arabinose and 2-deoxy-2,4-di-C-methyl arabinose via the enantiomeric 3-C-methyl-l-erythronolactone [from 2-C-methyl-d-ribono-lactone or d-ribose] and 3-C-methyl-d-erythronolactone [from d-tagatose or l-ribose]. NMR studies on unprotected C-methyl arabinoses show that methyl branching significantly affects the ratios of pyranose and furanose forms present in aqueous solution. © 2009 Elsevier Ltd. All rights reserved

High yield protection of alcohols, including tertiary and base sensitive alcohols, as benzhydryl ethers by heating with diphenyldiazomethane in the absence of any other reagent

A protecting group that can be introduced efficiently without the need for any acid or base catalysis and which is not prone to acid or base catalysed migration is a significant advantage for many syntheses. Benzhydryl [diphenylmethyl] ethers of sugar lactones are formed in high yield under neutral conditions when the corresponding alcohol is heated with diphenyldiazomethane in an inert solvent such as acetonitrile or toluene; this allows the easy protection of base sensitive and highly hindered tertiary alcohols in the absence of any other reagents. © 2008 Elsevier Ltd. All rights reserved

Carbon-branched carbohydrate chirons: practical access to both enantiomers of 2-C-methyl-ribono-1,4-lactone and 2-C-methyl-arabinonolactone

Readily crystallized 2-C-methyl-d-ribono-1,4-lactone is formed in a one-pot procedure from d-glucose without any protecting groups by treatment with dimethylamine to give an Amadori ketose and then with aqueous calcium hydroxide in yields of approximately 25%; 2-C-methyl-l-ribono-1,4-lactone is similarly produced from l-glucose. 3,4-O-Isopropylidene-2-C-methyl-d-arabinono-1,5-lactone and 2-C-methyl-d-arabinono-1,4-lactone were prepared in a combined 60% yield by the Kiliani reaction of sodium cyanide with a protected 1-deoxy-d-ribulose derived from d-erythronolactone; the enantiomeric arabinonolactones are similarly available from l-erythronolactone. © 2008 Elsevier Ltd. All rights reserved

Inhibition of nonmammalian glycosidases by azetidine iminosugars derived from stable 3,5-di-O-triflates of pentoses.

Efficient ring closure of stable crystalline 3,5-di-O-triflates of pentofuranosides with amines to form azetidines allowed preliminary evaluation of four-ring iminosugars as glycosidase inhibitors; significant and specific inhibition of nonmammalian α-glucosidases is shown by L-xylo- and L-arabino-iminosugar azetidines