L,2:4,5-di-0-cyclohexylidene

Two other myo-inositol derivatives have been selectively alkylated. Reaction of DL-l,2 4,5-di-0-cyclohexylidene-myo-inositol with benzyl chloride-potassium hydroxide in benzene, followed by removal of the acetal groups, gave DL-1-O- and DL-4-O-benzyl-myu-inositol in the ratio of 5 2, whereas, under similar conditions, DL-1,2 5,6-O-cyclohexylidene-myo-inositol gave311 the same ethers in the ratio of 57 10. These results are not readily explicable in the absence of knowledge of the conformations adopted by the cyclic acetals. 

Cognate preparations. l,2 4,5-Di-0-cyclohexylidene-D-fructopyranose. Add 200 g (1.11 mol) of finely powdered dry D-fructose with vigorous stirring to 419 g (440 ml, 4.49 mol) of ice-cooled cyclohexanone containing 30 ml of concentrated sulphuric acid the reaction mixture becomes solid within 30 minutes. Leave the mixture overnight at room temperature, dissolve the product in 500 ml of chloroform and wash the solution with dilute aqueous sodium hydroxide, dilute hydrochloric acid and water and finally dry and evaporate. Solidify the residue by m.p. 145-156°C, Md° —133.5° (cl in CHC13). The yield is 142 g (37%). 

A di-O-cyclohexylidene-D-fructose was prepared by treating a D-gluco-D-fnictan (shown to contain one D-glucose and about thirteen D-fructose residues) present in the tuber of the Hawaiian Ti plant with cyclohexanone containing 1.6% of sulfuric acid. The structure of the diacetal was not rigorously determined. It melted at 145° and showed [a]n —123° in acetone, and, on this basis, it was assigned the structure of l,2 4,5-di-0-cyclohexylidene-D-fructopyranose (94). 

Micovic and StojiljkoviC synthesized a di-O-cyclohexylidene-D-fructose, m.p. 142°, which, on the basis of its lack of reaction with alkaline potassium permanganate, was assumed to be l,2 4,5-di-0-cyclohexylidene-D-fructopyranose (94). They also prepared a syrupy di-O-cyclopentylidene-D-fructose, which was characterized as a crystalline p-toluenesulfonic ester it, too, did not react with alkaline potassium permanganate. 

The diacetal l,2 4,5-di-0-cyclohexylidene-jS-D-psicopyranose (107) has been prepared by reduction of l,2 4,5-di-0-cyclohexylidene-j -D-efi/fhro-2,3-hexodiulo-2,6-pyranose (106). 

Asymmetric epoxidation of rra/tv-alkenes in the presence of the fructose-derived 2,3-diulose derivative 15 afforded products with e.e. s of 70-95%, and an improved method for the conversion of l,2 4,5-di-0-cyclohexylidene-P-D-fructopyranose to the corresponding 3-ulose has been described. ... 

The syntheses of carba-P-o,L-fucopyranose and carba-P D,L-galactopyranose have been reported from 3-0-benzyl-l,2 4,5-di-0-cyclohexylidene-m> o-inositol. They involved the deoxygenation of the 6-OH, the conversion of the 1-OH into a ketone, and the addition of methylmagnesium bromide (for producing the fuco derivative) or benzyloxymethyllithium (for producing the galacto derivative) followed by deoxygenation and deprotection as the key step. ... 

Di- O -cyclohexylidene-a-D-allofuranose, C-189 1,2 5,6-Di- 0 -cyclohexylidene-3- C-ethyl-a-D-allofuranose, C-189 l,2 4,5-Di-0-cyclohexylidene-p-D-fructopyranose, F-84 1,2 5,6-Di- 0 -cyclohexylidene-a-D-glucofuranose, C-190 l,2 4,5-Di-0-cyclohexylidene-p-D-eryf/zro -hexo-2,3-diulose-2,6-pyranose, H-86... 

Di-0-benzylidene-p-D-fnictopyranose, F-84 2,3 4,5-Di-0-benzylidene-l-0-methyl-p-D-fructopyranose, F-84 2,3 4,5-Di-0-benzylidene-l-0-tosyl-p-D-fructopyranose, F-84 l,2 4,5-Di-0-cyclohexylidene-p-D-fnictopyranose, F-84 l,2 4,5-Di-0-isopropylidenefructopyranose D-form 3-O-Benzyl, D-714 l,2 4,5-Di-0-isopropylidenefructopyranose D-form, D-714 l,2 4,5-Di-0-isopropylidenefructopyranose D-form, D-714 2,3 4,5-Di-0-isopropylidenefructopyranose D-form, D-715 2,3 4,5-Di-0-isopropylidenefructopyranose D-form, D-715 3,4 5,6-Di-0-isopropylidene-D-ara6BM7-hex-2-uIosonic acid, H-111 l,2 4,5-Di-0-isopropylidene-3-0-mesyl-P-D-fructopyranose, D-714 l,2 4,5-Di-0-isopropylidene-3-C-methyl-p-D-fructopyranose, M-248 2,3 4,5-Di-0-isopropylidene-l-0-methyl-P-D-fructopyranose, D-715 2,3 4,5-Di-0-methylenefructopyrauose -D-form, D-729... 

By use of standard chemistry, lD-3-0-benzyl-l,2 4,5-di-0-cyclohexylidene-myo-inositol has been converted into the carba-disaccharide 78 as a potential intermediate for preparing glycosylphosphatidyl inositols. ... 

Di-0-cyclohexylidene-a-D-mannopyranosyl chloride, M-42 1,2 5,6-Di-0 -cyclohexylidene-3- O -mesyl-a-D-allofuranose, C-189 l,2 5,6-Di-0-cyclohexylidene-3-C-methyl-a-D-allofuranose, C-189 1,2 3,4-Di-0 -cyclohexylidene-6- O -tosyl-a-D-galactopyranose, G-193 1,2 5,6-Di-0 -cyclohexylidene-3-O -tosyl-a-D-glucofuranose, C-190 l,2 5,6-Di-0-cyclohexylidene-3-C-vinyl-a-D-allofuranose, C-189 l,2 3,5-Di-0-cyclohexylidene-a-D-xylofuranose, C-191 l,2 3,5-Di-(9-cyclohexylidene-a-L-xylofuranose, C-191 Didanosine, D-548 4a,106-Didehydrobergenin, B-29 4, 5 -Didehydro-5 -deoxycytidine, D-333 2, 3 -Didehydro-3 -deoxytliymidine, S-76 4, 5 -Didehydro-5 -deoxyuridine, D-549... 

Shvets and co-workers [301] have described a new synthesis of the phosphatidyl-inositol (435) by phosphorylation of the orthoester (437), derived from 2,3 4,5-di-0-cyclohexylidene-L-wyo-inositol, with 1,2-di-O-stearoyl-L-glycerol 3-phosphate in... 

Dienic hydrocarbon residues may also be introduced into a sugar molecule. Certain C-glycosylated dienes (40a-40d) and (41a-41d) were synthesized291 1 30 by the reaction of 2,3 4,5-di-0-cyclohexylidene-aldehydo-D-xylose (and L-arabinose) with appropriate phosphonium ylides. It may be noted that compounds 40d and 41d are the first examples of C-glycosylated terpenes. 

Benzoyl-l,2 3,5-di-0-benzylidene-a-D-glucofuranose, B-27 3-0-Benzoyl-l,2 4,6-di-0-benzylidene-a-D-glucopyranose, B-26 3-0-Benzoyl-2,5-dibromo-2,5-dideoxy-D-arabinono-l,4-lactone, D-526 3- O -Benzoyl-1,2 5,6-di- O -cyclohexylidene-a-D-glucofuranose, C-190... 

More-detailed examination of the reaction between alkylidene(and arylmethylene)triphenylphosphonium ylides and aldehydo sugars was conducted9 8 -30 in our laboratory with 2,3 4,5-di-0-cycIohexylidene-aldehydo-D-xylose (and -L-arabinose), resulting in the preparation of l-C-alkyl-3,4 5,6-di-0-cycIohexylidene-1,2-dideoxy-D-xylo(and L-ara-hino)-hex-l-enitol (27a-27d and 28a-28d, respectivelyB([Pg.236]

Di-O-cyclohexylidene, 5-benzoyl l-0-Benzoyl-2,3 4,5-di-0-cyclohexyli-dene-ds-inositol [34361-63-2]... 

Di-0-benzoyl-4,6-di-0-methyl-(3-D-mannopyranosyl fluoride, M-43 2,3 5,6-Di-0-cyclohexylidene-a-D-mannofuranose, M-114 2,3 4,6-Di-0-cyclohexylidene-a-D-mannopyranosyl chloride, M-42 2,3 5,6-Di-0 -isopropylidene-a-D-mannofuranose, 1-71 2,3 5,6-Di-0-isopropylidene-a-L-mannofuranose, 1-71 2,3 5,6-Di-0-isopropylidene-a-D-mannofuranosyl bromide, M-26 2,3 5,6-Di-0-isopropylidene-a-D-mannofuranosyl chloride, M-27... 

The two -OH groups in l,2 5,6-di-0-cyclohexylidene-wii/o-inositol and its di-O-isopropylidene analog are trans. The X-ray crystal structure of the latter compound suggests that the ring is in a skew conformation with the 0-3 and 0-4 -OH groups both in ax positions, but NMR studies and ab initio calculations indicate that a mixture of the skew and chair conformations, with 0-3 and 0-4 both in eq positions, is present. Formation of a dibutylstannylene acetal presumably locks these two compounds in the latter conformation. 

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