Ethyl-3,3-dimethyl-propanol

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

METHYL-1-BUTANOL 2-METHYL-2-BUTANOL 2 2-DIMETHYL-l-PROPANOL ETHYL PROPYL ETHER METHYL-T-BUTYL ETHER BUTYLMETHYL ETHER... 

Powerful evidence for the intermediacy of a metaphosphorimidate of type 189 nevertheless comes from the product spectrum obtained on reaction of 202 with KOH in ethanol or propanol. The principal products dimethyl sulfide and potassium O-ethyl (or propyl) phosphoramidate can be readily rationalized in terms of the reaction sequence presented in the Scheme 138). 

In soft cheeses, such as Brie, Camembert, and Limburger, the following sulfur compounds were implicated 3-(methylthio)propanol, MT, DMS, DMDS, DMTS, dimethyl tetrasulfide, methyl ethyl disulfide, diethyl disulfide, 2,4-dithiapentane, 3-methylthio-2,4-dithiapentane, methional, 2,4,5-trithiahex-ane, 1,1-fe-methylmercaptodisulfide, methyl thioacetate (=methanethiol acetate), benzothiazole, methylthiobenzothiazole, methyl ethyl sulfonate, methyl methane thiosulfonate, thiophene 2-aldehyde, and H2S.34 Many of these were only present in small amounts Limburger cheese was notable for 13.2% of DMDS, 0.5% of methyl thioacetate, and 0.8% of DMTS. 

Figure 18. Correlations between the solubility of cmchonidme and the reported empirical polarity (A) and dielectric constants (B) of 48 solvents [66]. Those solvents are indicated by the numbers in the figures 1 cyclohexane 2 n-pentane 3 n-hexane 4 triethylamine 5 carbon tetrachloride 6 carbon disulfide 7 toluene 8 benzene 9 ethyl ether 10 trichloroethylene 11 1,4-dioxane 12 chlorobenzene 13 tetrahydrofuran 14 ethyl acetate 15 chloroform 16 cyclohexanone 17 dichloromethane 18 ethyl formate 19 nitrobenzene 20 acetone 21 N,N-drmethyl formamide 22 dimethyl sulfoxide 23 acetonitrile 24 propylene carbonate 25 dioxane (90 wt%)-water 26 2-butanol 27 2-propanol 28 acetone (90 wt%)-water 29 1-butanol 30 dioxane (70 wt%)-water 31 ethyl lactate 32 acetic acid 33 ethanol 34 acetone (70 wt%)-water 35 dioxane (50 wt%)-water 36 N-methylformamide 37 acetone (50 wt%)-water 38 ethanol (50 wt%)-water 39 methanol 40 ethanol (40 wt%-water) 41 formamide 42 dioxane (30 wt%)-water 43 ethanol (30 wt%)-water 44 acetone (30 wt%)-water 45 methanol (50 wt%)-water 46 ethanol (20 wt%)-water 47 ethanol (10 wt%)-water 48 water. [Reproduced by permission of the American Chemical Society from Ma, Z. Zaera, F. J. Phys. Chem. B 2005, 109, 406-414.]...

The (R)-(+)-chiral 1,4-diol 17b was easily prepared from L-(+)-dimethyl tartrate. Dimethyl tartrate was converted to the corresponding phenylethylidene derivative by treatment with 1,1-dimethoxy-l-phenylethane and cat. p-toluenesulfonic acid in refluxing benzene, followed by conversion to the diol 17b with excess phenylmagnesium bromide. The diol was purified by column chromatography on silica gel (hexane ethyl acetate =5 1), and recrystalization from a mixture of hexane and 2-propanol. 

Dimethyl-1,2,4-oxadiazole has no UV absorption above 200 nm. For 3-phenyl-1,2,4-oxa-diazole = 238 nm (a = 14000), for the 5-phenyl isomer = 250 nm (a = 16100), and for 3,5-diphenyl-1,2,4-oxadiazole 2maj = 245 nm (a = 37200) (ether) have been reported <64HCA942>. 3-Ethyl-5-phenyl-1,2,4-oxadiazole has 2n,ax(CHCl3 or 2-propanol) = 284 nm, while for the fluorescence maxfCHCh) = 310 nm has been observed <77JOCi555>. Hypochromism with increase in con-... 

Problem 13.4 Explain why (a) propanol boils at a higher temperature than the corresponding hydrocarbon b) propanol, unlike propane or butane, is soluble in H O (c) n-hexanol is not soluble in H O (dimethyl ether (CH,OCH,) and ethyl alcohol (CH,CH,OH) have the same molecular weight, yet dimethyl ether has a lower boiling point (-24°C) than ethyl alcohol (78°C). M... 

A new synthesis of ( )-menthofuran (155) has been described which involves a three-step reaction sequence from the cyclohexanone (152) via direct C-alkylation with ethyl 2-iodopropionate to give (153) (Scheme 35). Hydrolysis of the diester (153) with hydrochloric acid afforded 3,6-dimethyl-2,4,5,6,7,7a-hexahydrobenzofuran-2-one (154). The final step in the sequence was the conversion of the a,/3-unsaturated y-lactone ring into the furan ring by reduction with lithium aluminum hydride and 2-propanol to afford (i)-menthofuran (155) in satisfactory yield (80JOC1517). 

Poly(styrene-co-acrylonitrile) samples (SAN) have been fractionated through methanol-acetone or methanol-dichloromethane mixtures of stepwise-altered composition 108) through methanol/dichloromethane, n-hexane/dichloromethane, or methanol/acetone gradients109), cyclohexane/methyl ethyl ketone gradients 110), or (toluene — 1-propanol 50 50)/dimethyl formamide gradients111. Mixtures of ethylene cyanohydrin — ethylene carbonate 112) or cyclohexane — methyl ethyl ketone 113 have also been used for the separation of SAN copolymers. Both the latter systems as well as the n-hexane/dichloromethane gradient109) had the efficacy of fractionating SAN copolymers by composition. 

List B, giving examples of liquids where a degree of concentration is necessary before hazardous levels of peroxides will develop, includes several common solvents containing one ether function (diethyl ether, ethyl vinyl ether, tetrahydrofuran), or two ether functions (p-dioxane, 1,1 -diethoxyethane, the dimethyl ethers of ethylene glycol or diethylene glycol ), the secondary alcohols 2-propanol and 2-butanol, as well as the susceptible hydrocarbons propyne, butadiyne, dicyclopentadiene, cyclohexene and tetra- and deca-hydronaphthalenes. Checking stocks at 12 monthly intervals, with peroxidic samples being discarded or repurified, is recommended here [1],... 

A mixture consisting of 4 grams of l,2,3,4-tetrahydro-4,4-dimethyl-7-methoxy-isochromanedione-(l,3) (MP 95° to 97°C), 2.53 grams of 4-aminosulfonyl-phenyl-(2)-ethylamine and 150 ml of xylene was heated for 2 hours at its boiling point in an apparatus provided with a water separator. Thereafter, the reaction mixture was allowed to cool and was then vacuum-filtered, and the filter cake was recrystallized from n-propanol in the presence of activated charcoal. 2.9 grams (58% of theory) of l,2,3,4-tetrahydro-4,4-dimethyl-2-[p-aminosulfonylphenyl-(2)-ethyl]-7-methoxy-isoquinolinedione-(1,3), MP 203° to 205°C, of the formula below were obtained. 

Methylisobutylketone Dimethyl sulfoxide pentane Dimethyl sulfoxide pentane Ethanol 1-pentanol Ethyl acetate 1-propanol Ethyl ether 2-propanol Ethyl formate propyl acetate Formic acid... 

The low Sn2 reactivity of 1°-alkyl bromide, 2,2-dimethyl-1-bromopropane (neopentyl bromide, 2.5), is explained by steric hindrance to the required 180° alignment of reacting orbitals. However, under Sn 1 conditions, neopentyl bromide (2.5) reacts at roughly the same rate as other 1°-alkyl halides such as ethyl bromide. Ionization of alkyl halides to carbocation in SnI is the rate-determining step. Although the product from ethyl bromide is ethanol as expected, neopentyl bromide (2.5) yields 2-methyl-2-butanol (2.6) instead of the expected 2,2-dimethyl-1-propanol (neopentyl alcohol) (2.7). This is because once formed the ethyl carbocation can only be transformed by a substitution or elimination process. In the case of the neopentyl carbocation, however, the initially formed l°-carbocation may be converted... 

Bernsteinsaure (1-Hydroxy-1-methyl-ethyl)- (Terebansaure) E19a, 556 (En + 2-Propanol) Butandioate Dimethyl 3-Hydroxy-2-methyl- E21a, 733 (2-H - 2-CH3) Furan 2.5-Dimethoxy-3,4-methylen-dioxy-tetrahydro- E14a/1, 4-[3,4-(OH)2-THF + Br- CH2-C1] Monoperhexandisaure E13/1, 774 (Cl - O-OH)... 

Dimerization of ethyl 2-amino-2-cyanoacetate gives diethyl 5-aminoimidazole-2,4-dicar-boxylate (92) as in Scheme 53. At reflux temperatures in propanol, 1,1-dimethyl-1-phenacyl-hydrazinium bromide is converted into 2-benzyl-4-phenylimidazole (93). Again the cycliz-ation is a dimerization process (Scheme 53) (80AHC(27)24l). 

Klass (1984b) Piel (1993) Miller (1993). The oxygenate designations are MeOH, methanol EtOH, ethanol IPA, 2-propanol TBA, 2-methyl-2-propanol IBA, 2-methyl-l-propanol TAA, 2,2-dimethyl-l-propanol MTBE, methyl 2-methyl-2-propyl ether ETBE, ethyl 2-methyl-2-propyl ether DIPE, di-2-propyl ether TAME, methyl 2,2-dimethyl-l-propyl ether IPTBE, 2-propyl 2-methyl-2-propyl ether TAEE, ethyl 2,2-dimethyl-1-propyl ether. 

Ru/Co CpRu(PPh,)2Co(CO)4 54 Ethanol/80 Methane/1 Dimethyl ether/2 Methylethyl ether/3 Methyl acetate/2 Diethyl ether/3 -propanol/5 Ethyl acetate/3 [26]... 

The first group of sulphur compounds mentioned above can be defined as common fermentative sulphur volatiles (CFSV) and includes in our presentation ethylmercaptan (EtSH), dimethyl sulphide (DMS), diethyl sulphide (DES), dimethyl disulphide (DMDS), diethyl disulphide (DEDS), methyl thioacetate (MTA), ethyl thioacetate (ETA), 2-mercaptoethanol (ME), 2-(methylthio)-l-ethanol (MTE), 3-(methylthio)-l-propanol (MTP), 4-(methylthio)-l-butanol (MTB), benzothiazole (BT) and 5-(2-hydroxyethyl)-4-methylthiazole (HMT) (see Table 5.6). 

Throughout the Tables, the following abbreviations are used A, acetone AcOH, acetic acid B, benzene Bu, 1-butanol C, cyclohexane Ch, chloroform D, 1,4-dioxane Dch, dichloromethane Dip, diisopropyl ether E, ethanol EA, ethyl acetate Et, ether Ip, 2-propanol M, methanol Me2SO, dimethyl sulfoxide P, 1-propanol Pe, petroleum ether Py, pyridine Tch, tetrachloromethane T, toluene and W, water. 

A) Propanol B) Dimethyl ether C) Acetone D) Ethyl methyl ketone E) Propanoic acid... 

Polymerised preformed [(N,N -dimethyl-l,2-diphenylethane diamine)2Rh] complex allows us to obtain enantioselective material. We have then shown that it is possible to imprint an optically pure template into the rhodium-organic matrix and to use the heterogeneous catalyst in asymmetric catalysis with an obvious template effect. The study of yield versus conversion graphs has shown that the mechanism occurs via two parallel reactions on the same site without any inter-conversion of the final products. Adjusting the cross-linker ratio at 50/50 allows us to find a compromise between activity and selectivity. Phenyl ethyl ketone (propiophenone) was reduced quantitatively in 2 days to (R)-l-phenyl propanol with 7tf% enantiomeric excess We have then shown that the imprinting effect is obvious for molecules related in structure to the template (propiophenone, 4 -trifluoromethyl acetophenone). It is not efficient if the structure of the substrate is too different to that of the template. 

Figure 5.2. Volatile sulfur compounds of wines (15) dimethyl sulfide, (16) ethylmer-captan, (17) diethyl sulfide, (18) methyl thioacetate, (19) dimethyl disulfide, (20) ethyl thioacetate, (21) diethyl disulfide, (22) 2-mercaptoethanol, (23) 2-(methylthio)-l-ethanol, (24) 3-(methylthio)-l-propanol, (25) 4-(methylthio)-l-butanol, (26) 3-mercap-tohexan-l-ol, (27) 4-methyl-4-mercaptopentan-2-one, (28) 3-mercaptohexanol acetate, (29) benzothiazole, (30) 5-(2-hydroxyethyl)-4-methylthiazole, (31) fra s-2-methylthio-phan-3-ol, (32) 2-methyltetrahydrothiophen-3-one.

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