Dimethyl-2-phenyl-propanol

Dimethyl-2-phenyl-propanol PhCH2CMe20-H 104.2 435.8 Correlation 2004TUM/DEN(b)... 

Methyl-1-phenyl-propanol 2,2-Dimethyl-] -phenyl-propanol l 2,2,2-Trifluor-1 -phenyl-athanol... 

There are a number of other aryl-substituted carbodicationic systems that can be properly described as distonic superelectrophiles. For example, dication 45 has been generated from 2,2 -p-phenylenedi-2-propanol in SbFs at —78°C.4 When compared to the dimethyl(phenyl)carbenium ion (cumyl cation) 46, NMR data indicate that the positive charges are dispersed to a considerable extent into the neighboring methyl groups in the dication 45. 

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. 

Initially, Swem et al. reported the oxidation of sterically hindered alcohols to carbonyls with a dimethyl sulfoxide-trifluoroacetic anhydride complex.7 These reactants included primary alcohols such as 2,2-dimethyl-l-phenyl-propanol 3 and secondary alcohols, for example, 2-adamantanol 4. 

Hydrated silica (INCI). See Silica, hydrated Hydratropalcohol. See 2-Phenyl propanol-1 Hydratropaldehyde. See 2-Phenylpropanal Hydratropaldehyde dimethyl acetal. See 2-Phenylpropionaldehyde dimethylacetal Hydratropic alcohol. See 2-Phenyl propanol-1 Hydratropic aldehyde. See 2-Phenylpropanal Hydratropic aldehyde dimethyl acetal. See2-Phenylpropionaldehyde dimethylacetal Hydratropyl acetate... 

Photolysis, apparatus for, 55, 17 Phthalimide, N-amino- [ 1//-Isoindole-1,3-(2//)-dione, 2-amino-, 55, 115 Potassium rew-butoxide [2-Propanol, 2-methyl-, potassium salt], 55,12, 13 Potassium iodide, 55, 71 Potassium permanganate [Permanganic acid, potassium salt], 55,68 Propane, 2,2 dimethyl 1 phenyl, 55, 112 Propane, 2 isocyano-2-methyl-, 55, 96... 

Recently Mosher and Driscoll 2 have noted that the polymerization of acrylonitrile can be observed during the chromic acid oxidation of 2,2-dimethyl-l-phenyl-l-propanol. The polymerization is caused by radicals formed during the oxidation of benzaldehyde (which is one of the cleavage product of phenyl-1-butylcarbinol). The oxidation of benzaldehyde is due to the chromium(IV), most probably, or chromiun(V) intermediates. 

In an enantiomer-differentiating oxidation at a poly-(L-valine)-coated Pb02 anode, rac-2,2-dimethyl-l -phenyl-1 -propanol was partially oxidized leaving 43% optically pure (5)-alcohol [371]. At a TEMPO-modified graphite felt anode rac-1-phenyl-ethanol has been enantioselectively oxidized in the presence of (-[-sparteine leaving 46% of the (/ [-alcohol with 99.6% ee [372]. However, under the same conditions, an exclusive dehydrogenation of (-[-sparteine to the iminium salt without oxidation of the alcohol was found [373]. 

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-... 

If a diastereomeric mixture of (S,S)-2,5-dimethyl-3.4-hexanediol esters 2 and 3 reacts with methylmagnesium bromide, the result is kinetic resolution, as verified for R1 = Bn. The diastereomeric mixture was prepared from the racemic ethylene glycol a-chloro boronic ester via transesterification with chiral diol. The products isolated were (S,S)-2,5-dimethyl-3,4-hexanediol [(/ )-2-phcnyl-l-methylethyl]boronate, diastereomeric ratio >95 5 as indicated by the rotation of the (/ )- -phenyl-2-propanol derived by deboronation with hydrogen peroxide, and (S,S)-2,5-dimethyl-3.4-hexanediol methylboronate. Phenylacetaldehyde was identified by 1H NMR4. 

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. 

The first practical method, using C2-symmetric chiral phosphine 1 as catalyst, was disclosed in 1996 by Vedejs [39]. Employing (3-Cl-C6H4C0)20 (2.5 equiv.) as the acylating agent in the presence of phosphine 1 (16 mol%), various aryl alkyl sec-alcohols were surveyed and s-values of 12 to 15 were obtained for the optimal substrate 2,2-dimethyl-l-phenyl-l-propanol (Scheme 8.3). 

Alkylated barbituric acids, 6-chloro-a-methylcarbazole-2-aceticacid, 1-phenylethanol, 1-phenyl-1-propanol, dimethyl, 3,4,5,6-pentafluoro-benzyl alcohol, l-(2-naphthyl)-ethanol, 1 -(p-biphenyl)-ethanol Chirasil-Dex coated column, 0.15 pm... 

Propanol l-Chlor-3-(4-methyl-phenyl)- Vl/la, 2, 1263 Spiro[2.4 hepta-4,6-dien l -Chlor-2,2-dimethyl-l-methoxy- E19b, 1660 (Carben + En)... 

Komori and Nonaka [499] reported the first example of an electrochemical enantiomer-differentiating reaction When racemic 2,2-dimethyl-1-phenyl-1-propanol was oxidized at a poly(L-valine)-coated anode, 43% optically pure (S)-(—)-2,2-dimethy 1-1-phenyl-1-propanol was recovered as an unreacted part. Yamagishi and Aramata [500] also found electrooxidative optical resolution of a racemic Co(l,10-phenathroline)3 complex by a chiral clay-coated anode, and Yoshinaga and coworkers [501] electrore-ductively resolved racemic Co(acetylacetonato)3 by using optically active supporting electrolytes. 

Among the numerous examples of Spjl reactions that occur with incomplete race-mization is one reported by Winstein in 1952. The optically pure tosylate of 2,3-dimethyl-l-phenyl-l-propanol ([ ]u = -30.3 ) was heated in acetic acid to yield the corresponding acetate ([aJo = + 5.3°). If complete inversion had occurred, the optically pure acetate would have had [ )o = +53.6°. What percentage racemizationand what percentage inversion occurred in this reaction ... 

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