4,4 ,4"-Tris trityl bromide

Alcohols r-Butyldiphenylchlorosilane. 2-Benzyloxy-l-propene. Bis(iso-propylthio)boron bromide. /-Butyl me thox-yphenylsilyl bromide. 2,3-Dichloro-5,6-di-cyano-l,4-benzoquinone. Mercury(II) chloride.4,4, 4"-Tris(4,5-dichlorophthalam-ido)trityl bromide. Tetramethylguanidine. Aldehydes Lithium morpolide. Organotitan-ium compounds. 

Tris(benzoyloxy)trityl bromide selectively protects the primary hydroxy group in nucleosides. It is more stable than trityl under acid conditions, but is base-labile. It was applied to the synthesis of 3 -substituted thymidines carrying 3 -acid-... 

Attempts66 to prepare the 2,3-anhydride from methyl 3-0-(methyl-sulfonyl)-/3-maltoside, using M sodium methoxide, resulted in the corresponding 3,6-anhydride 43. To circumvent the formation of 43, the reaction was performed with methyl 3-0-(methylsulfonyl)-6,6 -di-0-trityl-/3-maltoside. The desired product, methyl 2,3-anhydro-4-0-(2,3,4-tri-0-acetyl-6-0-trityl-a-D-glucopyranosyl)-6-0-trityl-/3-D-allopyrano-side (44), was obtained in 72% yield. Attempted detritylation of 44 by brief treatment with hydrogen bromide in glacial acetic acid, followed by conventional acetylation, gave methyl 2,6,2, 3, 4, 6 -hexa-0-acetyl-... 

Selective O-tritylation of a primary hydroxyl group of L-arabinose diethyl dithio-acetal (116) with trityl chloride and 4-dimethylaminopyridine (DMAP), successive benzylation with benzyl bromide, and O-detritylation with p-toluenesulfonic acid, followed by tosylation gave 2,3,4-tri-0-benzyl-5-0-tosyl-L-arabinose diethyl dithio-acetal (777), [a]J,8 —2° (chloCEoform). Cleavage of the diethyl dithioacetal group with... 

The constitution and configuration of cellobiose was confirmed by synthesizing the sugar, though in very small yield. This was the first synthesis of cellobiose by way of a trityl compound. Methyl 2,3,6-tri-acetyl-/S-D-glucopyranoside (XXVII) was condensed with tetraacetyl-D-glucopyranosyl bromide and the condensation product identified as methyl heptaacetyl-(8-cellobioside (XXVIII). Since the latter compound yields acetobromocellobiose (heptaacetylcellobiosyl bromide) and cello-... 

Heterocycles Acetylacetone. N-Aminophthalimide. Boron trichloride. Dichloro-formoxime. Oicyanodiamide. Dicyclohexylcarbodiimide. Dietboxymethyl acetate. Diethyl oxalate. Diketene. Dimethylformaniide diethylacetal. Diphenyldiazomethene. Ethyl ethoxy-methylenecyanoacetate. Formaldehyde. Formamide. Formamidine acetate. Formic acid. Glyoxal. Hydrazine. Hydrazoic acid. Hydroxylamine. Hydroxylamine-O-sulfonic acid. Methyl vinyl ketone. o-Phenylenediamine. Phenylhydrazine. Phosphorus pentasullide. Piperidine. Folyphosphoric acid. Potassium diazomethanedisulfonate. Sodium ethoxide. Sodium nitrite. Sodium thiocyanate. Tetracyanoethylene. Thiosemicarbozide. Thiourea. Triethyl orthoformate. Tris-formaminomethane. Trityl perchlorate. Urea. Vinyl triphenyl-phosphonium bromide. 

A most important theoretical study was presented by Hennig on the possible reaction-mechanisms involved in the formation of cyclic and keto derivatives during acetylation (see Scheme III). When 1 mole of 3,4,5-tri-0-acetyl-l,6-di-0-trityl-fcefo-D-fructose (a) is treated at room temperature with two moles of acetyl bromide in acetic anhydride, 1,3,4,5-tetra-... 

Attempted detritylation of methyl 4-0-benzyl-2,3-dideoxy-6-0-trityl-a-D-en/thro-hex-2-enopyranoside with hydrogen bromide caused addition to the double bond and also 1,6-anhydride formation, to give l,6-anhydro-4-0-benzyl-3-bromo-2,3-dideoxy-D-arafcino-hexose,938 so that the addition is related to that occurring when tri-O-acetyl-D-glucal is treated with this reagent in acetic acid.18... 

The initial basic substance for the synthesis of fluotrimazole (45), l-(3-tri-fluoromethyltrityl)-lH-1,2,4-triazole, may be wi-trifluoromethylphenyl bromide (48), which reacts in Grignard synthesis with benzophenone (49), the 3-tri-fluoromethylphenyl-bis(phenyl)methylcarbinol (46) obtained being converted into trityl chloride (47). 

Trisiamylborane, 216 Tris(methylthio)methyllithium, 412 Tris(trimethylsilyl) phosphite, 412-413 Tiis(triphenylsilyl)vanadate, 413-414 Triton, B., 20, 72, 91, 133 2-(p-Tritylphenyl)sulfonylethanol, 414 2-(p-Tritylphenyl)thioethaiiol, 414 Trityl tetrafluoroborate, 414-415 Tropylium bromide, 369 Tryptamine, 358 Tryptophan, 78, 135 Tryptophan-kynurenine conversion, 261-262... 

The quaternary salt formed from tetra-O-acetyl-a-D-galactopyranosyl bromide and trimethylamine yields l,6-anhydro-/3-D-galactopyranose on treatment with barium hydroxide 122). During treatment of tri-O-acetyl-5-0-trityl-D-ribofuranose with hydrogen bromide, a trityl and an acetyl group are removed with the formation of 2,3-di-0-acetyl-l,5-anhydro-D-ribofuranose 123) (shown by other workers to be dimeric). 

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