Methyl 1,5-dithio

C6H12O3S2 0.25 H20 Methyl 1,5-dithio-a-D-ribopyranoside, tetartohydrate MDTRPY20 32 358... 

The reaction of p-D-ribopyranose tetraacetate (63) with methanethiol and zinc chloride gave 32), after deacetylation, methyl 1-thio-p-D-ribo-pyranoside (64), methyl 1,5-dithio-p-D-ribopyranoside (72, R=H), 4-S-methyl-4-thio-L-lyxose dimethyl dithioacetal (77, R=H), and a small... 

The other two known examples of intramolecular H-bonds within a monosaccharide unit in the crystalline state occur in two thio-sugars, methyl-l-thio and methyl-1,5-dithio-a-D-ribopyranoside (40) (illustrated in Figure 3). As far as we know, these are the first examples of syn-diaxial O-H O bonding in a cyclic carbohydrate in the solid state. It is not certain now, whether any particular significance should be associated with the fact that these are thio sugars. 

Fig. 13.8. Details of the intramolecular hydrogen bonds in the two symmetry-independent molecules in the crystal structure of methyl 1,5-dithio-o-ribopyranoside quarterhydrate [MDTRPY20]...

The -D chair conformation is also stabilized in the crystalline state by the formation of an intramolecular hydrogen bond in both methyl-1,5-dithio-a-ribopyranoside quarterhydrate [MDTRPY20] and methyl-1-thio-a-ribopyranoside [MTRIBP 10]. In the former structure there are two symmetry-independent molecules with different directions for the 0(2)H to 0(4)H bond, as shown in Fig. 13.8. In the methyl-1 -thio-a derivative the direction is 0(2)H 0(4) and the bond forms part of an infinite chain, as shown in Fig. 13.9. In the methyl-1,5-dithio-a-ribopyranoside quarterhydrate, the hydrogen-bond direction is 0(4)H 0(2) in one molecule and 0(2)H 0(4) in the second crystallograph-ically independent molecule in the same crystal structure. As shown in Fig. 13.10, the intramolecular hydrogen bond is part of a cyclic arrangement of eight bonds,... 

Fig. 13.10. Hydrogen-bonding pattern in the crystal structure of methyl 1,5-dithio-a-D-ribopyra-noside quarterhydrate. Four molecules form a hydrogen-bonded cluster around the water molecule. The perimeter of the cluster is hydrophobic and the packing of the 4(C6H1203S2)-H20 clusters is van der Waals. Note the eight-membered homodromic cycle and the homodromic spiral involving the water molecule. The swivel indicates hydrogen bonding to the next asymmetric unit [MDTRPY20]...

P2,2,2i Z = 4 Dx = 1.479 R = 0.07 for 660 intensities. The conformation is C4, with three axially attached hydroxyl groups, two of which, O-2-H and O-4-H, are linked by an intramolecular hydrogen-bond. Similar intramolecular hydrogen-bonding has been observed in the crystal structures of methyl 1-thio-a-D-ribopyranoside and methyl 1,5-dithio-a-D-ribopyranoside.13 This is the same crystal structure as that given in a preliminary report,14 which did not include the atomic parameters. 

Desulfurization by refluxing with Raney nickel in 70% ethanol for 6 hours converted thiol esters to aldehydes in 57-73% yields (exceptionally 22% yield) [1101] ( Procedure 6, p. 205). Desulfurization of a dithioester, methyl dithio-phenylacetate, by refluxing with Raney nickel in 80% ethanol for 1 hour afforded 65% yield of ethylbenzene [1102]. 

Acyloin 213 with thioamides, thiosemicarbazides, and methyl dithio-carbazate in trifluoroacetic acid give photochromic thiazole-, thiadiazine-, and pyrazole-bridged dihetarylethenes 254,255, and 256-258, respectively (Scheme 72) (OlIZVllS, 06ZOR882). 

Perfluoroalkylamines can be prepared from perfluoroalkanethioamides67 and methyl dithio-carbamates.6B-6t)... 

DIETHYL-S-(4-0X0-3H-l,2,3-BENZ0TRIAZINE-3-YL)-METHYL-DITHIOPHOSPHATE see EKNOOO 0,0-DIETHYL-S-(4-0X0BENZ0TRIAZIN0-3-METHYL)PHOSPHORODITHIOATE see EKNOOO 0,0-DIETHYL-S-((4-0X0-3H-l,2,3-BENZ0TRIAZIN-3-YL)-METHYL)-DITHIO FOSF, AT (DUTCH) see EKNOOO... 

A mixture of 0.225 g (0.68 mmol) of 0-[(Z)-4-phenyi-2,2-bis(2-propenyl)-3(Z)-pentenyl] S-methyl dithio-carbonate. 0.224 g (0.77 mmol) of tributyltin hydride and O.Oi i g of AIBN in 35 mL of thiophene free, degassed dry toluene are heated at 80 JC with stirring for 1 h under an argon atmosphere. The solvent is then removed under reduced pressure. The pale yellow oil is purified by flash column chromatography on silica gel (CcH6) to give the desired product yield 0.138 g (71 %). 

Synonyms 0,0-dimethyl-S-(3,4-dihydro-4-keto-l,2,3-benzotriazinyl-3-methyl)dithio-... 

The di-5-methyl-dithio derivatives (52) and (53), respectively, of fructose and sucrose have been obtained by standard methods from the corresponding free sugars. Compound (52) is twenty times sweeter than sucrose, whereas the sucrose analogue (53) is only slightly sweet. Oxidation of the sulphide groups to sulphoxides or sulphones destroys the sweetness in both cases. ... 

CsHigClCoNSe H2O, (Methyl dithiocarbazate-N, S)bis[methyl dithio-carbazato(1-)-N, S]cobalt(III) chloride monohydrate, 45B, 1287 CgHi eCl2CoNi,Sa 0.5 C3H8N2S2r Dichlorobis(methyl 2-methyldithio-carbazato-N, S)cobalt(II) methyl 2-methyldithiocarbazate solvate, 46B, 1204... 

Easily prepared thiocarbonyl derivatives of alcohols, such as the 5-methyl dithio-carbonates (64 Y == SMe), can be treated with soft electrophiles A-X to improve the leaving ability of the alcohol oxygen in the presence of a nucleophile and thus provide a simple mild method of hydroxy group replacement (Scheme 27). For instance, use of CH3I as the electrophile produces alkyl iodides, and sulphenyl halides PhSX can be utilized to synthesize chlorides, bromides, or iodides. Similar reactions have been described for some selenocarbonyl alcohol derivatives. ... 

Hydantoin, 5,5-diaryl-2,4-dithio-methylation, 5, 444 Hydantoin, 1,3-divinyl-polymers, 1, 280 Hydantoin, 5-methylene-polymers, 1, 280 Hydantoin, 5-phenyl-2-thio-tautomerism, 5, 370 Hydantoin, thio-... 

Lumazine, 6,7-diphenyl-5,6-dihydro-properties, 3, 306 UV spectrum, 3, 279 Lumazine, 6,7-diphenyl-2-thio-glycosidation, 3, 297 reactions, 3, 300 Lumazine, 6,7-diphenyl-4-thio-reactions, 3, 300 Lumazine, 2,4-dithio-methylation, 3, 299 Lumazine, l-/3-D-glucopyranosyl-NMR, 3, 282 Lumazine, 1-hydroxy-structure, 3, 282... 

Uric acid, 9-methyl-2,8-dithio-, 5, 590 Uric acid, 9-phenyl-synthesis, 5, 577 Uric acid, 8-thio-synthesis, 5, 577, 582 Uric acid, 1,3,7-trimethyl-ethylation, 5, 534 methylation, 5, 535 Uric acid, 1,7,9-trimethyl-methylation, 5, 535 Uridine... 

Diseleno acetals and ketals are cleaved more rapidly than their dithio counterparts a methyl derivative is cleaved more rapidly than a phenyl derivative. Methyl iodide or ozone converts diseleno acetals and ketals to vinyl selenides. ... 

Chemical Name N-[(4-Amino-2-methyl-5-pyrimidinyl)methyl] -N -[4-hydroxy-1-methyl-2-[(tetrahydrofurfuryl)dithio] -1 -butenyi] formamide... 

CN 6-(aceiylthio)-8-[[2-[[(4-amino-2-methyl-5-pyrimidinyl)methyl]formylamino]-l-(2-hydroxycthyl)-l-propenyl]dithio]octanoic acid methyl ester... 

The reaction of the aldehyde 174, prepared from D-glucose diethyl dithio-acetal by way of compounds 172 and 173, with lithium dimethyl methyl-phosphonate gave the adduct 175. Conversion of 175 into compound 176, followed by oxidation with dimethyl sulfoxide-oxalyl chloride, provided diketone 177. Cyclization of 177 with ethyldiisopropylamine gave the enone 178, which furnished compounds 179 and 180 on sodium borohydride reduction. 0-Desilylation, catalytic hydrogenation, 0-debenzyIation, and acetylation converted 179 into the pentaacetate 93 and 5a-carba-a-L-ido-pyranose pentaacetate (181). 

As a solvent for this reaction, anhydrous methyl ethyl ketone was found satisfactory. Coates (10) determined the rate of hydrolysis of the monothio analog as approximately one fifth that of tetraethyl pyrophosphate under similar conditions. The dithio analog has been prepared (22) in 90% yield from diethyl chlorothiophosphate, water, and pyridine in a modification of the reaction Toy (47) used to make tetraethyl pyrophosphate ... 

Figure 25 Structure of bis[methyl(w-hexyl)dithio-/selenocarbamato]-zinc and -cadmium complexes,...

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