Hexopyranose derivatives synthesis

T.-M. Cheung, D. Horton, and W. Weckerle, Preparative synthesis of 3-amino-2,3,6-trideoxy-L-/yv<9-hexopyranose derivatives, Carbohydr. Res., 74 (1979) 93-103. 

D. Lafont, P. Boullanger, O. Cadas, and G. Descotes, A mild procedure for preparation of 1,6-anhydro-jS-D-hexopyranoses and derivatives, Synthesis, (1989) 191-194. 

Since the mid-1980s, Kunz and co-workers started an exploration of asymmetric synthesis using sugar template-based chiral auxiliaries. Their early success on this topic is particularly shown by their demonstration of the utility of six-membered pento- and hexopyranose derivatives such as per-O-pivaloylated /3-D-galactosylamine [42,43,44,45,46,47,48,49,50]. The collective studies of the Kunz group have been thoroughly reviewed [51,52]. 

Our interest in GOase came from a need to find an efficient process for making 5-C-hydroxymethyl-L-arabino-hexopyranose derivatives 1 (Equation 1). These compounds have been developed as candidates for nonnutritive sugar substitutes in foods because they resist metabolism and have sucrose-like functional properties (7). These materials would be too expensive if made using the techniques of traditional chemical synthesis, so we developed a simple "one-pot" process (Equation 1) using GOase. 

Treatment of the branched 3-deoxy-D-ribo-hexopyranose derivative (1) with propane-l,3-dithiol and aqueous HQ gave the 2,5-anhydro compound (4) in 80% yield (Scheme 1). The reactiim is thought to proceed via the expected acyclic dithioacetal (2) and to involve the well known elimination of a hydroxyl group P to a dithioacetal function, followed by an unprecedented intramolecular H -catalysed additmi to the p-carbon of theketoie dithioacetal (3). The synthesis of KDO by use of bis(ethylthio) intermediates is referred to in Qiapter 16. 

Conformational analyses by n.m.r. and computational methods have been reported for the following compounds l,2-anhydro-3,4,6-tri-0-benzyl-P-D-talopyranose, anhydro sugars 13 and similar hexopyranose derivatives, methyl 3,4-0-isopropylidene-a- and P-D-galactopyranoside and their di-O-acetates and di-O-methyl ethers, 3,4-0-(/ )-benzylidene-D-ribono-1,5-lactone (see Chapter 6), and 6-deoxy-6-phosphonoyl-D-fructopyranoses (see Chapter 17 for synthesis). D-Glucospyranosylamine, its tetra-O-acetate and 4,6-0-benzylidene acetal and several N-acylated derivatives, together with D-[l- C]glucopyranosylamine, have been used in a conformational study by n.m.r. spectroscopy aimed at probing the existence of the reverse anomeric effect. ... 

Suarez et al. have reported a general method for the synthesis of alduronic acid lactones via fragmentation of carbohydrate anomeric alkoxy radicals [124] (Scheme 77). Treatment of hexopyranose derivative of the galacturonic acid, 342, with (diacetoxyiodo)benzene and iodine under mild conditions or with... 

With respect to five-membered lactones fused to hexopyranose units, some approaches have been reported so far and the exploitation of their synthetic potential has led to the access of new carbohydrate derivatives. Bicyclic derivatives of this type are key intermediates in the synthesis of the epimer at C-3 of the sugar moiety contained in miharamycins [212, 213]. The latter are antibiotics known to inhibit strongly Pyricularia oryzae, which produces the rice blast disease. These compounds are also considered to be a potential bioterrorism agent (Scheme 42). Hence, the 3,3-spiroepoxide 176 was converted into the 3-C-cyanomethyl derivative 177, the hydrolysis of which led to spontaneous cyclization in the presence of... 

M. Sharma, R. J. Bernacki, M. J. Hillman, and W. Korytnyk, Fluorinated carbohydrates as potential plasma membrane modifiers. Synthesis of 3-deoxy-3-fluoro derivatives of 2-acetamido-2-deoxy-D-hexopyranoses, Carbohydr. Res., 240 (1993) 85-93. 

T. Tmka, M. Cerny, M. Budesinsky, and J. Pacak, The synthesis of 3-amino-3-deoxy-D-glucose (Kanosamine) and its 1,6-anhydro derivative. Conformation of amino derivatives of l,6-anhydro-/S-D-hexopyranoses, Collect. Czech. Chem. Commun., 40 (1975) 3038-3045. 

Jotterand, N. et al. Total Asymmetric Synthesis of Doubly Branched Carba-hexopyranoses and Amino Derivatives Starting from the Diels-Alder Adducts of Maleic Anhydride to Furfuryl Ester. 3.4.3 1999 (133]... 

Jotterand, N, Vogel, P, Schenk, K, Total asymmetric synthesis of doubly branched carba-hexopyranoses and amino derivatives starting from the Diels-Alder adducts of maleic anhydride to furfuryl esters, Helv. Chim. Acta, 82, 821-847, 1999. 

During the past ten years, the l,6-anhydro-/3-D-hexopyranoses have found wide application in the synthesis of hexoses and their derivatives, and of oligosaccharides, and for polymerization to polysaccharides. They can be used as model compounds in studying the physical and chemical properties of monosaccharides, as has been shown, for example, by nuclear magnetic resonance (n.m.r.) studies, and also by studies of (a) their chiroptical properties, (b) the partial reactivity of hydroxyl groups, and (c) their ability to form complexes. 

Like dianhydrohexopyranoses, 1,6 2,3-dianhydro-4-deoxy- and 1,6 3,4-dianhydro-2-deoxy-/3-D-hexopyranoses (30, 131-133) may be utilized for synthesis of derivatives of 2- or 4-deoxy derivatives of 1,6-anhydrohexopyranoses (see Sect. VII,3,b). 

The synthesis of a 1,4-oxazepane based 1,6-anhydro-P-D-hexopyranose, 142, has been reported in good overall yield (48%) from the tosylate 139, via the derivatives 140 and the... 

Reductive cyclization by lithium aluminum hydride as the key step has been employed for the preparation of O-benzylated l,6-anhydro-2,3-dideoxy-2,3-epi-mino- and l,6-anhydro-3,4-dideoxy-3,4-epimino-p-D-hexopyranoses having the alio-, manno-, galacto-, and to/o-configurations from suitable 1,6 2,3- and l,6 3,4-dianhydro-p-D-hexopyranoses. Stereoselective trara-diaxial cleavage of the oxirane ring was effected by treatment with sodium azide and ammonium chloride in a 2-methoxyethanol-water mixture at 110-120 °C. Synthesis of 1,6-anhydro-4-(9-benzyl-2,3-dideoxy-2,3-epimino-p-D-marmopyranose (7) from di-anhydro derivative 4 illustrates this methodology. An alternative reduction by sodium borohydride in THF was also tested in the preparation of the 2,3-d-u//o-and D-ma u-epimines in this series. It provided a better yield (73%) than... 

J. S. Brimacombe and K. M. M. Rahman, Synthesis of a derivative of D-kijanose (2,3,4,6-tetradeoxy-4-methoxycarbonylamino-3-C-methyl-3-nitro-D-xyto-hexopyranose), Carbohydr. Res, 123 (1983) C19-C21. 

The total synthesis of all four 3,6-dideoxy-DL-hexoses and all four 3-deoxy-DL-hexoses has been achieved by stereospecific hydroxylations of butyl 2-acetoxy-tra j -hex-4-enoate and butyl 2-acetoxy-6-hydroxy-tran5-hex-4-enoate, respectively. In an alternative synthesis 3,6-dideoxy-DL-arabino- and -DL-ribo-hexopyranoses were prepared from the Diels-Alder adduct derived from methyl... 

The amide 24, an intramediate in synthesis of methyl 4,6-dideoxy-4-(3-deoxy-L-g(ycero-tetronamido)-a-D-truuinopyranoside, t-butyl-NA -dibenzyl-2-(l,2 5,6-di-0-isopropylidene-a-I>-allofuranose-3-yl)-L-glycirutle 25, 3 2-deoxy-2-hydroxyimino derivatives 26 and 27 of fi-D-arabino-hexopyranose, and 23,4,S-tMra-0-ace l-6-amino-6-deoxy-D-galactonolactam.9S TheN-glycosidic... 

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