Diacetone glucose

Di-0-isopropylidene-D-glucose (diacetone-D-glucose Aldrich Chemical Company, Inc., 98%) was used without purification. 

Diacetone glucose" "Diacetone galactose" "Dicyclohexylidene mannose"... 

Xyhtol also is obtained by sodium borohydride reduction of D-xylonic acid y-lactone (32) and from glucose by a series of transformations through diacetone glucose (46). 

Most current industrial vitamin C production is based on the efficient second synthesis developed by Reichstein and Grbssner in 1934 (15). Various attempts to develop a superior, more economical L-ascorbic acid process have been reported since 1934. These approaches, which have met with htde success, ate summarized in Crawford s comprehensive review (46). Currently, all chemical syntheses of vitamin C involve modifications of the Reichstein and Grbssner approach (Fig. 5). In the first step, D-glucose (4) is catalytically (Ni-catalyst) hydrogenated to D-sorbitol (20). Oxidation to L-sotbose (21) occurs microhiologicaRy with The isolated L-sotbose is reacted with acetone and sulfuric acid to yield 2,3 4,6 diacetone-L-sorbose,... 

The inverse electron-demand catalytic enantioselective cycloaddition reaction has not been investigated to any great extent. Tietze et al. published the first example of this class of reaction in 1992 - an intramolecular cycloaddition of heterodiene 42 catalyzed by a diacetone glucose derived-titanium(IV) Lewis acid 44 to give the cis product 43 in good yield and up to 88% ee (Scheme 4.31) [46]. 

Danishefsky s diene 154 DBFOX 232 dendrimers 229 DPT calculations 308 diacetone glucose derived-titanium(IV) 178 diastereoselectivity 216 diazo compounds 242 diazoalkane cycloadditions 278 diazoalkanes 213, 231 (R,R)-4,6-dibenzofurandiyl-2,2 -bis(4-phenylox-azoline) 250... 

Reagent 7 is easily prepared from commercially available diacetone-D-glucose and trichloro(cyclopentadienyl)titanium35 (Section 1.3.3.3.8.1.). The monomeric structure of reagent 7 was confirmed by an X-ray crystal structure analysis1 7. Complex 9 is obtained36 analogously from (7 .7 )-tartaric acid derived (R,7 )-2,3-CMsopropylidene-l,l,4,4-tetraphenyl-1,2,3,4-butanetetrol. 

The Merck compound MK-0608 is a 2 -C-Me-7-deaza-adenosine analog, which has recently been reported to show a 5.7 log drop in viral load in HCV-infected chimpanzees after dosing QD at 2mg/kg (Olsen 2006). An efQcient and practical process for preparing kilogram quantities has been described (Bio et al. 2004). The 12-step synthesis provides an impressive 35% overall yield and starts from the inexpensive diacetone-D-glucose. The synthesis features a novel acyl migration in route to prepare the key crystalline furanose diol intermediate (Fig. 5). The conditions... 

Ziegler and Saprong described a stoichiometric cyclization onto an alkyne for the synthesis of the carbocyclic core of entecavir from diacetone glucose. Inverse addition was required to minimize deoxygenation. The highly diastereoselective reaction is tolerant to silylethers [101]. 

In equation 8.2-6a, the slope of -1 with respect to pH refers to specific hydrogen-ion catalysis (type B, below) and the slope of + 1 refers to specific hydroxyl-ion catalysis (Q if k0 predominates, the slope is 0 (A). Various possible cases are represented schematically in Figure 8.5 (after Wilkinson, 1980, p. 151). In case (a), all three types are evident B at low pH, A at intermediate pH, and C at high pH an example is the mutarotation of glucose. Cases (b), (c), and (d) have corresponding interpretations involving two types in each case examples are, respectively, the hydrolysis of ethyl orthoacetate, of P -lactones, and of y-lactones. Cases (e) and (f) involve only one type each examples are, respectively, the depolymerization of diacetone alcohol, and the inversion of various sugars. 

L-aspartic acid L-tartaric acid Diacetone-D-glucose... 

Versuche zu Totalsynthesen in der Prostaglandinreihe, by P. de Roche (1973). Oxydation von D-Glucose und von Diaceton-L-sorbose mit Sauerstoff, by F. Bacber (1976). 

L-Mannitol does not occur naturally but is obtained by the reduction of L-mannose or L-mannonic acid lactone (80). It can be synthesized from the relatively abundant L-arabinose through the L-mannose and L-glucose cyanohydrins, conversion to the phenylhydrazines which are separated, liberation of L-mannose, and reduction with sodium borohydride (81). Another synthesis is from L-inositol (obtained from its monomethyl ether, quebrachitol) through the diacetonate, periodate oxidation to the blocked dialdehyde, reduction, and removal of the acetone blocking groups (82). 

To a solution of diacetone glucose 11 (0.4 g, 1.5 mmol) in 5 mL of pyridine were successively added 1 mL of hexamethyldisilazane and a 0.5 mL of chlorotrimethylsilane. The solution was stirred for 30 min at room temperature and evaporated to dryness. To a solution of the crude silylated ether in CH2C12 (10 mL) were added 2.5 mL of Bu4NF (1M in THF) and A iV -sulfuryldiimidazole (0.46 g, 1.5 eq.). The solution was refluxed for 4 h, diluted with CH2C12, washed twice with water, dried (Na SC ), and evaporated. Flash chromatography of the residue (ether-petroleum ether, 2 1) gave the imidazylate 12 (0.55 g, 91%) mp 98.5°-99.5°C (ether-hexane). 

K. Freudenberg and F. Brauns, Zur kenntnis der Aceton-zucker, 1 Umwandlungen del Diaceton-Glucose, Chem. Ber. 55 3233 (1922). 

To a solution of diacetone-a-D-glucose [Eq. (9)] 28 (2.60 g, 10 mmol), jV-hydroxy-succinimide (NHS, 0.115 g, 1 mmol), and dry pyridine (2.43 mL, 30 mmol) in THF (50 mL) was added 4-fluorophenyl chlorothionoformate (3.81 g, 20 mmol) dropwise at room temperature under argon. The solution was stirred for an additional 2 h. The organic layer was washed with 1 M HC1, saturated NaHCOj, brine, and dried over anhydrous MgS04. After evaporation of the solvent under reduced pressure, the thionocarbonale by-product was precipitated with hexanes. After filtration and evaporation, the crude product was purified by column chromatography over silica gel (eluting with n-hexane-CHjClj, 7 3) to afford 3.13 g (76%) of the thionocarbonate 32 mp 82°-83°C (EtOH-H20) [a], —33° (c 1, CHClj). 

K. Kakinuma, Y. Iihama, I. Takagi, K. Ozawa, N. Yamauchi, N. Imamura, Y. Esumi, and M. Uramoto, Diacetone glucose architecture as a chirality template. II. Versatile synthon for the chiral deuterium labelling and synthesis of all diastereomers of chirally monodeuterated glycerol, Tetrahedron 48 3163 (1992). 

K. M. Sun, R. Guiliano, and B. Fraser-Reid, Diacetone glucose derived dienes in Diels-Alder reactions. Products and transformations, J. Org. Chem. 50 4114 (1985). 

B. Fraser-Reid, Z. Benko, R. Guiliano, K. M. Sun, and N. Taylor, Complete stereospecificity in the intramolecular Diels-Alder reaction of an ester derived from diacetone glucose, J. Chem. Soc. Chem. Commun. p. 1029 (1984). 

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