2.2- Dimethyl-l-phenylpropane

Methyl-A -2-octalone, A54.6 10-Methyl-A -l-octalone, A54.9 lO-Methyl-A -2-octalone, A53.13 2,2-Dimethyl-l-phenylpropan-l-ol, A 19,19 2-Methyl-l-phenylbutan-2-ol, A 28.6... 

When benzene reacts with l-chloro-2,2-dimethylpropane (neopentyl chloride) in the presence of aluminum chloride, the major product is 2-methyl-2-phenylbutane, not 2,2-dimethyl-l-phenylpropane(neopentylbenzene). Explain this result. 

Among the numerous examples of SnI reactions that occur with incomplete racemization, the optically pure tosylate of 2,2-dimethyl-l-phenylpropan-l-ol ([a]o = 30.3) gives the corresponding acetate ([ ]d = +5.3) when heated... 

The photo-stimulated reaction of l-iodo-2,2-dimethyl-3-phenylpropane (49) with the enolate ion of acetone in DMSO and an excess of r-BuOK gives reduction product (50) and unexpectedly, l,l-dimethyl-2-phenylcyclopropane (51). Evidence is presented for a mechanism involving the deprotonation of the benzylic carbon to give a carbanion (52), which gives (51) by an intramolecular nucleophilic substitution. 

Methyl-l-phenylpropane, see Isobutylbenzene 2-Methyl-2-phenylpropane, see ferf-Butylbenzene Methyl phthalate, see Dimethyl phthalate... 

Hydroperoxy-2-nitropropane, 256 p-Hydroquinone, 331,393,418 p-Hydroquinone dimethyl ethers, 432 Hydroquinones, 72 Hydrosilylation, 562 Hydroxamic acids, 204 2-Hydroximino-l-phenylpropane, 124 ai-Hydroxyacetophenone, 342 (3-Hydroxyacetylenes, 144-145 a-Hydroxy acids, 492 (5-Hydroxy acids, 301 1-Hydroxyadamantane, 126 a-Hydroxyaldehydes, 342 3o-Hydroxy-5a-androstene-17-one, 227-228... 

A mixture of 3,6-dimethyl-3,6-dibenzyl-s-tetrathiane (prepared from phenyl-acetone) and LiAlH4 refluxed 6 hrs. in ether 2-mercapto-l-phenylpropane. Y 86%. — Mercaptans may be prepared from ketones via these polythiohetero-cyclics. F. e. s. F. O. and P. A. Bobbin, B. 98, 998 (1965). 

Thus, when 2,2-dimethyl-, 2-methyl-2-n-propyl- and 2-methyl-2-iso-amylpropane-l,3-diol were treated with diethyl carbonate in the presence of catalytic amounts of sodium methoxide, only PCs were produced in high yield. On the other hand, six-membered cyclic carbonates are exclusively produced when 2,2-diethyl-, 2-ethyl-2-phenylpropane-1,3-diol, pentane-2,4-diol, 2-methylpentane-2,4-diol, and butane-1,3-diol were subjected to the transesterification reaction (Scheme 10). 

B. Cydopropylbenzene. In a 1-1. three-necked flask equipped, with a stirrer and a thermometer extending into the flask but free from the stirrer are placed 500 ml. of redistilled dimethyl-formamide and zinc-copper couple prepared from 131 g. (2 g. atoms) of zinc (Note 8). The mixture is cooled to 7° in an ice bath, and 1,3-dibromo-l-phenylpropane is added to the stirred mixture at a rate sufficient to maintain the reaction temperature at 7-9° (Note 9). The mixture is stirred for 30 minutes after the addition is completed, poured into 1 1. of water, and then steam-distilled until the condensate is homogeneous or 11. of water has been collected. The organic layer is separated from the distillate, and the aqueous layer is extracted with three 100-ml. portions of ether. The combined organic portions are washed with four 50-ml. portions of water and dried over anhydrous potassium carbonate. The ether is removed by distillation at atmospheric pressure at water bath temperature. The residue is distilled to give 88-100 g. (75-85%) of cydopropylbenzene, b.p. 170-175° (Note 10), 26d 1.5306-1.5318. 

SYNS l,l-DIMETHOXY-2-PHENYLPROPANE HYDROTROPALDEHTOE DIMETHYL ACETAL 2-PHENYLPROPIONALDEHYDE DIMETHYL ACETAL... 

Debromination. Benzylic bromination of 3-bromo-l-phenylpropane gives the 1,3-dibromo derivative in nearly 100% yield. A mixture of 500 ml. of dimethyl-formamide and 2 g. atoms of zinc copper couple (method 2) is stirred at 7° and the... 

An analogous stereochemical outcome was observed when the ethylation of racemic 2-phenyl-propanal was catalyzed by (-)-(/ )-l-(diisopropylamino)-3,3-dimethyl-2-butanol36. The reaction was run to 70% conversion and again the ratio of syn- to anff-diastercomers was 3 1. In this case, however, the 7 -configurated aldehyde was predominantly consumed and both enantiomers of the aldehyde were predominantly alkylated from the Re-side. The optical purity of the unreacted (S)-2-phenylpropanal was 85.7% ee. 

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