3- Chloro-2,3-dimethyl-2-butanol

Problem 28.9 The following reactions have all been found to yield a mixture of pinacol and pinacolone, and in the same proportions treatment of 3-amino-2,3-dimethyl-2-butanol with nitrous acid treatment of 3-chloro-2,3-dimethyl-2-butanol with aqueous silver ion and acid-catalyzed hydrolysis of the epoxide of 2,3-dimethyl-2-butene. What does this finding indicate about the mechanism of the pinacol rearrangement ... 

Treatment of <%-chloro alcohols (chlorohydrins) with a base leads to epoxides (oxiranes).lh Epoxide formation is appreciably favored by alkyl substituents thus, tetramethylethylene chlorohydrin (3-chloro-2,3-dimethyl-2-butanol)... 

Problem 17.47. Draw the stereoisomers, if any, of each of the following (a) 1,1-dimethyl-l-propanol, (b) 2-methyl-l-propanol, (c) 1-propanol, id) 1-methyl-1-propanol, (e) 3-chloro-2-butanol, (/) 2,3-butanediol. 

AI3-00040, see Cyclohexanol AI3-00041, see Cyclohexanone AI3-00045, see Diacetone alcohol AI3-00046, see Isophorone AI3-00050, see 1,4-Dichlorobenzene AI3-00052, see Trichloroethylene AI3-00053, see 1,2-Dichlorobenzene AI3-00054, see Acrylonitrile AI3-00072, see Hydroquinone AI3-00075, see p-Chloro-rrr-cresol AI3-00078, see 2,4-Dichlorophenol AI3-00085, see 1-Naphthylamine AI3-00100, see Nitroethane AI3-00105, see Anthracene AI3-00109, see 2-Nitropropane AI3-00111, see Nitromethane AI3-00118, see ferf-Butylbenzene AI3-00119, see Butylbenzene AI3-00121, see sec-Butylbenzene AI3-00124, see 4-Aminobiphenyl AI3-00128, see Acenaphthene AI3-00134, see Pentachlorophenol AI3-00137, see 2-Methylphenol AI3-00140, see Benzidine AI3-00142, see 2,4,6-Trichlorophenol AI3-00150, see 4-Methylphenol AI3-00154, see 4,6-Dinitro-o-cresol AI3-00262, see Dimethyl phthalate AI3-00278, see Naphthalene AI3-00283, see Di-rj-butyl phthalate AI3-00327, see Acetonitrile AI3-00329, see Diethyl phthalate AI3-00399, see Tributyl phosphate AI3-00404, see Ethyl acetate AI3-00405, see 1-Butanol AI3-00406, see Butyl acetate AI3-00407, see Ethyl formate AI3-00408, see Methyl formate AI3-00409, see Methanol AI3-00520, see Tri-ocresyl phosphate AI3-00576, see Isoamyl acetate AI3-00633, see Hexachloroethane AI3-00635, see 4-Nitrobiphenyl AI3-00698, see IV-Nitrosodiphenylamine AI3-00710, see p-Phenylenediamine AI3-00749, see Phenyl ether AI3-00790, see Phenanthrene AI3-00808, see Benzene AI3-00867, see Chrysene AI3-00987, see Thiram AI3-01021, see 4-Chlorophenyl phenyl ether AI3-01055, see 1.4-Dioxane AI3-01171, see Furfuryl alcohol AI3-01229, see 4-Methyl-2-pentanone AI3-01230, see 2-Heptanone AI3-01231, see Morpholine AI3-01236, see 2-Ethoxyethanol AI3-01238, see Acetone AI3-01239, see Nitrobenzene AI3-01240, see I idine AI3-01256, see Decahydronaphthalene AI3-01288, see ferf-Butyl alcohol AI3-01445, see Bis(2-chloroethoxy)methane AI3-01501, see 2,4-Toluene diisocyanate AI3-01506, see p,p -DDT AI3-01535, see 2,4-Dinitrophenol AI3-01537, see 2-Chloronaphthalene... 

A-4. Hydrolysis of 3-chloro-2,2-dimethylbutane yields 2,3-dimethyl-2-butanol as the major product. Explain this observation, using structural formulas to outline the mechanism of the reaction. 

For example, the synjanti product ratio of the base-promoted dehydrochlorination of mes o-3,4-dichloro-2,2,5,5-tetramethylhexane with potassium t-butoxide to give (Z)- and ( )-3-chloro-2,2,5,5-tetramethyl-3-hexene changes from 92 8 in tetrahy-drofuran (ej. = 7.6) and 86 14 in t-butanol (er = 12.5) to 7 93 in dimethyl sulfoxide (fir = 46.5) [694]. 

Robison, and Robison were the first to prepare 7-azagramine (3-dimethylaminoniethyl-7-azaindole), finding the following procedure to give optimum yields. The azaindole, 10% excess dimethyl-amine hydrochloride, and one molar equivalent of paraformaldehyde are refluxed together in w-butanol for 30 minutes, followed by evaporation under reduced pressure. The residue is extracted with dilute acid, from which the base is precipitated with sodium carbonate. This procedure has been used with only minor variations on a variety of 7-azaindoles. Williamson obtained 7-azagramine in 99% yield on a 0.2-mole scale, compared to 81%. Other 7-azagramines prepared similarly are l-phenyl-4-methyl (72%), ° l-butyl-4-methyl (64%), 6-chloro-4-methyl (60%), 4-methyl (28%), 2-methyl, and 5-methyl (60%). In the case of the last two 4-methyl compounds, it was found that the best yields were obtained with use of a 3 1 molar ratio of dimethylamine hydrochloride and only a 15-minute reflux period. With the 6-chloro-4-methyl isomer, some (6%) of the bis-(7-aza-3-indolyl)methylene by-product was formed. 

C5H10O2 2,2-dimethyl-3-hydroxypropionaldehyde 597-31-9 409.77 35.287 2 5634 C5H11CIO 3-chloro-2-methyl-2-butanol 21326-62-5 414.65 35.748 1,2... 

Normal nucleophilic substitution reactions of alkyl and aryl chloropyrazines have been examined as follows 2-chloro-3-methyl- and 3-chloro-2,5-dimethyl(and diethyl)pyrazine with ammonia and various amines (535, 679, 680) 2-chloro-3(and 6)-methylpyrazine with methylamine and dimethylamine (681, 844), piperidine and other amines (681, 921) 2-chloro-5(and 6)-methylpyrazine with aqueous ammonia (362) alkyl (and phenyl) chloropyrazines with ammonium hydroxide at 200° (887) 2-chloro-3-methylpyrazine with aniline and substituted anilines (929), and piperazine at 140° (759) 2-chloro-3-methyl(and ethyl)pyrazine with piperidine (aqueous potassium hydroxide at reflux) (930,931) [cf. the formation of the 2,6-isomer( ) (932)] 2-chloro-3,6-dimethylpyrazine with benzylamine at 184-250° (benzaldehyde and 2-amino-3,6-dimethylpyrazine were also produced) (921) 2-chloro-3,5,6-trimethylpyrazine with aqueous ammonia and copper powder at 140-150° (933) and with dimethylamine at 180° for 3 days (934,935) 2-chloro-6-trifluoromethylpyrazine with piperazine in acetonitrile at reflux (759) 2-chloro-3-phenylpyrazine with aqueous ammonia at 200° (535) 2-chloro-5-phenylpyrazine with liquid ammonia in an autoclave at 170° (377) 2-chloro-5-phenylpyrazine with piperazine in refluxing butanol (759) but the 6-isomer in acetonitrile (759) 5-chloro-2,3-diphenylpyrazine and piperidine at reflux (741) and 5-chloro-23-diphenylpyrazine with 2-hydroxyethylamine in a sealed tube at 125° for 40 hours (834). 

Preparations of the corresponding hydrazino compounds from 2-chloro-3(or 6)-methylpyrazine and 2-chloro-3,6-dimethylpyrazine with 98% hydrazine in absolute ethanol at reflux (775) and from 2-chloro-3,5-dimethyl-, 2-chloro-3,5,6-trimethyl-, 2-chloro-5- and 6-methyl-3-propyl-, or 2-chloro-5,6-dimethyl-3-propylpyrazines with excess hydrazine hydrate in a sealed tube at 110-130° for 24 hours or for a similar period under reflux in butanol (826) have been described. 

Sodium-f-Butanol-Tetrahydrofurane, 291 Sodium /-butoxide, 305 Sodium chloride-Dimethyl sulfoxide, 445 Sodium chloroacetate, 275 Sodium N-chloro-p-to/uenesulfonamide, 75, 445-446... 

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