Heptitols acetylation

C19H23BrO10S 4,5,7-Tri-0-acetyl-2,6-anhydro-l-0-(p-bromophenylsul- fonyl)-3-deoxy-D-gluco-heptitol BACGLO 31 369... 

In similar fashion, 6-nitro-6-desoxysorbitol gives 87 percent of the acetylated nitroolefin, L-zyfo-tetraacetoxy-l-nitrohexene-l, without purification of the intermediate, sirupy nitroalcohol pentaacetate.54 1-Nitro-1-desoxy-D-arabitol tetraacetate30 gives, in the Schmidt and Rutz reaction, 81 percent of D-en/fftro-triacetoxy-l-nitropentene-1 1-nitro-l-desoxy-D-manno-D-graZa-heptitol hexaacetate42 similarly gives 90 percent of D-marmo-pentaacetoxy-l-nitroheptene-1. 

From the oxo reaction of 3,4,6-tri-O-acetyl-D-galactal (36) (after deacetylation of the mixture of products), there was obtained, in almost quantitative yield, 2,6-anhydro-3-deoxy-D-golacto-heptitol (37) and 2,6-anhydro-3-deoxy-D-foio-heptitol (38). - Structural investigations of these anhydrodeoxyalditols paralleled those on the alditols obtained from 3,4,6-tri-O-acetyl-D-glucal. The absolute structures of compounds (37) and (38) were unequivocally established by correlation, as shown, with 2,6-anhydro-3-deoxy-D-gZuco-heptitol (27). Prior structural work" on compound (37), with the aid of periodic acid degradations only, had led to an incorrect, tentative assignment of structure. 

Attempts to use 4,5,7-tri-0-acetyl-2,6-anhydro-l,3-dideoxy-l-iodo-D-giuco-heptitol for x-ray analysis were unsuccessful, because only twinned crystals could be prepared. Use of die deacetylated p-toluenesulfonate, namely, 2,6-anhydro-3-deoxy-l-0-p-tolylsulfonyl-D-gl co-heptitol, and of the parent alditol, 2,6-anhydro-3-deoxy-D-glaco-hepti-tol, was unsuccessful because no atom of sufficient electron density was present. 

Application of the oxo reaction to tetra-0-acetyl-l-deoxy-D-arob no-hex-l-enopyranose (49) (2-acetoxy-tri-O-acetyl-D-glucal ) produced mainly one product which, on deacetylation with sodium methoxide, readily afforded 2,6-anhydro-D-g/ycefo-D-gttZo-heptitol (50) in 70% yield. This compound had previously been described by Coxon and Fletcher, and their structural proof was used in the assignment of structure to compound (50). 

From the oxo reaction of tetra-O-acetyl-l-deoxy-D-Zt/xo-hex-l-eno-pyranose (51), with dicobalt octacarbonyl as the catalyst, followed by deacetylation of the mixture of products, the expected heptitol, namely, 2,6-anhydro-D-gZt/cero-L-manno-heptitol (52), was produced in much lower yield (about 20 %). 

The conversion of tetra-0-acetyl-l-deoxy-D-arabtno(and o-lyxo)-hex-l-enopyranose into 2,6-anhydro-D-gIj/cero-D-guIo(and L-manno)-heptitol, respectively, provides chemical proof that the oxo reaction proceeds by way of cis addition of hydroxymethyl and hydrogen to the carbon—carbon double bond. 

Application of the oxo reaction at 100—110° for 20 minutes to tri-O-acetyl-l,2-anhydro-D-glucopyranose (Brigl s anhydride) (73), followed by acetylation, gave, in over 80% yield, 1,3,4,5,7-penta-O-acetyl-2,6-anhydro-D-gli/cero-D-gttlo-heptitol (74), identical with an authentic sample. Reduction of the minor component [presumed to be the aldehydo precursor of (74)] with sodium borohydride, followed by acetylation, afforded the acetylated heptitol (74). 

An isolated example of the use of x-ray diflraction analysis is provided by the work of Camerman and coworkers. Hydroformyl-ation of 3,4,6-tri-O-acetyl-D-glucal gave 4,5,7-tri-0-acetyl-2,6-anhydro-3-deoxy-D-gIuco- and -D-manno-heptitols, which were converted into the corresponding 1-p-bromobenzenesulfonates. One of these sulfonates was shown hy x-ray analysis to have the CJ(d) conformation in which all of the substituents are oriented equatorially hence, this sulfonate was the D-gluco isomer. 

Tetra-0-acetyl-2,6-anhydro-1-deoxy-D-g(/ycero-D-g(u/o-heptitol... 

Hydroformylation in benzene solution with hydrogen and carbon monoxide in the presence of dicobalt octacarbonyl303 afforded, after deacetylation, 2,6-anhydro-D-g/ycero-D-gu/o-heptitol, with two unidentified, minor products.55 Likewise, 2-acetoxy-tri-O-acetyl-D-galactal afforded mainly 2,6-anhydro-D-g/i/cero-L-mcnno-heptitoI on similar treatment. Methoxymercuration of the D-glucal derivative gave a crystalline glycoside adduct, obtained in 18% yield, which, on... 

Fig. 8.—Separation of Alditol Acetates. (Key (A) tetra-O-acetylerythritol (B) penta-0-acetylribitol (C) penta-0-acetylxylitol (D) hexarO-acetjdallitol (E) hexa-0-acetyl-D-iditol (F) hepta-O-acetyl-meso-jij/cero-ollo-heptitol (G) hepta-O-acetyl-D-(//j/cero-D-monno-heptitol (H) hepta-O-acetyl-n-jlycero-D-ffluco-heptitol and (I) octa-0-acetyl-D-erylAro-L-po/ocIo-octitol. Conditions column (120 x 0.5 cm.) of a 1 1 (v/v) mixture of the two following packings (1) 1 1 (w/w) mixtures of (a) 20% w/w butane-diol succinate on Chromosorb W, 60-80 mesh, and (b) 20% w/w Apiezon M grease on silver-coated Chromosorb W, 60-80 mesh, with (2) 0.3% w/w Apiezon M grease on silver-coated glass-beads, 60-plus mesh 213° 200 ml. of argon/min. /3-ionization detector.)...

T etra- 0-acetyl-2,6-anhy dro-1 -deoxy-1 -nitro-D-glycero-D-gulo-heptitol (14) [34] (4.0 g, 10.2 mmol)... 

Acetylated derivatives have been used in the characterization of dialdose dianhydrides, partially methylated heptitols, and aldobiuronic acid methyl ester methyl glycosides. The origin of the fragments with even mass numbers derived from alditol acetates is based on elimination of keten, acetic acid, and acetic anhydride. ... 

Hepta Ac Hepta-O-acetyl-D- ycQxo-L-%d 2LCX.o-heptitol C21H30O14 506.46 Mp 118°. [a]o +11.4 (CHCI3). 

H ta-O-acetyl-4-O-a-D-glucopyranosyl-a-D-glucopyranosyl bromide, M-15 H ta- O -acetyl-D-g/yc ro -L-galacto -heptitol, H-14... 

Di-0-acetyl-2,6-anhydro-D-idopyranose, A-658 D-g/ycero-L-gw/o-Heptitol 2,6-Anhydro, penta-Ac, H-17 D-g/ycero-L-gw/o-Heptitol 2,6-Anhydro, pentabenzyl, H-17... 

Improved procedures for the preparation and g.c. analysis of peracetylated aldoses have been developed. Acetylation (AcjO-l-raethylimidazole) can be performed directly on acid hydrolysates, and factors influencing the ratios of isomers produced have been studied. This method was compared with the alditol acetate procedure for the quantitative analysis of four plant materials. G.l.c.-m.s. data have been reported for partially methylated and acetylated derivatives of L-gfycero-n-manno- and n-gfycero-D-manno-heptoses and -heptitols. ... 

Amino- and Imino-Alditols.- The synthesis of 1,2-diamino-dideoxy-D-g/yccro-L-manno- and D-g/ycero-L-g/uco-heptitol and their conversion into the same pyrazine (23) on reaction with benzil followed by acetylation and oxidation has been rqx>rted. ... 

Alditols. Cvclitols and Derivatives Thereof.- D-Arabinitol, D-altritol, Ti-gtycero-H-mcmno-and D-g/ycero-D- /Mco-heptitols, D-g/yc ro-L-ga/acro-hcptitol, racemic perseitol (D-g/yccro-D- fl/octo-heptitol and its enantiomer), 4-0-P-D-galactopyranosyl-D-glucitol dihydrate (lactitol), hexa-O-acetyl-D-glucitol," " penta-0-acetyl-xylitol," and methyl 1,5-di-O-acetyl-3,4-bis-0-(bicyclophosphoranylato)quinate. ... 

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