Tris methyl derivatives

Betaine is the tetra-methyl ammonium inner salt compound already referred to (p. 386). It is really a tri-methyl derivative of glycine. 

Gleiter et al. measured the He(Ia) photoelectron (PE) spectra of the parent heterocycle and its five mono-, di-, and tri-methyl derivatives, and assigned the PE bands by comparison with the results of MO calculations <83CPL(97)94>. They showed that the spectral assignment was consistent with the results of four very different theoretical procedures (HMO, EWMO, HAM/3, and LOGO MB). Recently, it has been reported that the PE spectra were reproduced well by the Outer-Valence Green Function approach with PM3 <91JCS(P2)1865> (see Table 3). 

Chlorine, under reduced temperature and in an inert solvent, reacts with closo-1,5-C2B3H5 to produce 2-Cl-l,5-C2B3H4- In a hot/cold reactor, BMc3 and 1,5-C2B3HS form a mixture of B-mono-, -di-, and -tri-methyl derivatives of the c/oso-carbaborane. The dimer 2,2 -C2B3H4—C2B3H4 and B-methyl derivatives are also produced ... 

Angier and Marsico followed the course of alkylation first. The 7-dimethylamino-5-methylmercapto derivative reacted with dimethyl sulfate in an alkaline medium to yield a mixture of the 2- and 3-methyl derivatives. The reaction of the 7-diraethylamino derivative with ethyl iodide in an alkaline medium led to a mixture of all three possible monoethyl derivatives. The position of the alkyl group in all these substances was defined by comparing the UV spectra with derivatives prepared by a straightforward synthesis. After reacting the mercuric salts with tri-0-benzoylribofuranosyl chloride, they demonstrated the ribose residue to be bound in position 2. The same structure was shown to be valid for the derivative prepared by Andrews and Barber. ... 

The enantiomerically pure isobomeol allyl sulfoxide derivatives (17 ,2Y,3/ ,4S )-1,7,7-tri-methyl-3-[(S)- or -(/ )-2-propenylsulfmyl]bicyclo[2.2.1]heptan-2-ol are thermally more stable inversion of configuration at sulfur, S -> / , occurs at 135-145 °C. Their lithio derivatives give exclusively y-1,4-adducts with 2-cyclopentenone19. 

Dediazoniation of three o-substituted benzenediazonium salts in pyridinium poly(hydrogen fluoride) yields different products depending on the substituent, as Olah and Welch (1975) have found. The 2-methyl derivative gives 2-fluoro-toluene. With the 2-nitrobenzenediazonium ion the main product is 3-nitrofluoro-benzene, the 2-isomer being formed only in small quantities. Finally, the 2-tri-fluoromethyl derivative yields all three isomeric trifluoromethylfluorobenzenes. 

The isothiazide ligand, (142), and its 3- and 5-methyl derivatives form the tris complexes IrCl3(isothiazole)3 in which isothiazole and the 5-methyl derivative bind through the S atom, whereas 3-methylisothiazole binds through the N atom.254... 

The ligands phenylene-l,2-dithiolate, or its 4-methyl derivative, have been thoroughly studied in their gold(I) complexes and di-, tri-, and tetranuclear derivatives have been prepared of the type... 

Okamoto et al [85] performed the optical resolution of primaquine and other racemic drugs by high performance liquid chromatography using cellulose and amylose tris-(phenylcarbamate) derivatives as chiral stationary phases. Primaquine and other compounds were effectively resolved by cellulose and/or amylose derivatives having substituents such as methyl, tertiary butyl, or halogen, on the phenyl groups. 

Methylation was accomplished by direct conversion of the acetyl derivative as previously described. The final product contained 45% OCHs. Molecular weight determinations in benzene gave values representing 18 to 19 D-fructose residues. Hydrolytic products of the methyl derivative were separated by conversion to benzoyl derivatives. The trimethylfructose was identified as 3,4,6-trimethyl-D-fructofuranose by its phenylosazone. The authors conclude that the ratios 1 3 1 exist among the di-, tri-, and tetramethyl-D -fructoses produced by the hydrolysis. 

Methylgraminin was obtained as a colorless sirup by the method of Haworth and Streight.24 Hydrolysis of the methyl derivative gave a mixture of di-, tri-, and tetramethyl-D-fructoses that were separated after conversion to benzoyl derivatives. The authors conclude that these partially methylated D-fructoses are present in the ratios 1 1 1 or 1 2 1. 

An anhydride whose formula is represented by XVII would yield a mixture of 3,4,6-trimethyl-D-fructose and 1,3,6-trimethyI-D-fructose when its hexamethyl derivative was hydrolyzed. Available data concerning di-D-fructose anhydride II are at least in accord with this structure, and if the present inferences are accepted, one may conclude that the rotation of 1,3,6-trimethyl-D-fructose is near those of 1,4,6- and 3,4,6-tri-methyl-D-fructose. 

Partially methylated derivatives of D-glucosone have been prepared by decomposition of the corresponding partially methylated phenylosazones with p-nitrobenzaldehyde osones have been obtained from 5-0-methyl-D-glucose phenylosazone and from 3,4,5-tri-O-methyl-D-glucose phenylosazone in this way.22 Although 6-0-methyl-D-glucose phenylosazone is not altered by heating with benzaldehyde or piperonal in aqueous ethanolic... 

Many other glycosides have been subjected to selective chlorination with sulfuryl chloride. Methyl /3-L-arabinopyranoside afforded methyl 4-chloro-4-deoxy-a-D-xylopyranoside 2,3-di(chlorosulfate) in 29% yield, whereas the a-L anomer gave357 methyl 3,4-dichloro-3,4-dideoxy-/3-i)-ribopyranoside 2-(chlorosulfate) (30%). Methyl /3-d-ribopyranoside was converted into methyl 3,4-dichloro-3,4-dideoxy-a-L-arabinopyranoside through the action of pyridine hydrochloride on its 2,3,4-tri(chlorosulfate).358 Methyl a-D-lyxopyranoside gave only the 2,3,4-tri(chlorosulfate),353 as would be expected from the disposition of its hydroxyl groups, similar to that in the rhamno- and manno-pyranosides. Methyl a-D-altropyranoside was transformed into the 6-chloro-6-deoxy 2,3,4-tri(chlorosulfate) derivative in 80% yield.353... 

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