2-chloro-2-phenylpropane

The 2 1 adduct 308 obtained from 303 with 2-chloro-2-phenylpropane (reaction 42) is probably derived from the addition of 303 to a-methylstyrene (307)626. 

Compound V eliminates magnesium bromofluoride and is probably converted to an epoxide, which rearranges to compound W, 2-chloro-2-phenylpropanal. Elimination of magnesium bromofluoride instead of magnesium bromochloride is probably due to stronger affinity of magnesium to fluoride ion [108]. 

Many other substituent parameters have been developed to improve correlations for specific types of reactions. Brown and Okamoto (1958) developed substituent constants (electrophilic reactions based on hydrolysis rates of meta- and para-substituted 2-chloro-2-phenylpropanes (CPP), which react by electrophilic carbonium ion intermediates. Formation of these intermediates is facilitated by high electron density at the reactive carbon (i.e., by meta- or para-electron donors). The parameter meta substituents), k0 is the hydrolysis rate constant for unsubstituted CPP, and k is the rate constant for a substituted CPP. 

Rates. Hydrolysis of the tertiary benzylic halide 2-chloro-2-phenylpropane occurs 620 times faster than hydrolysis of tert- miy chloride under the same conditions (90% acetone—10% water at 25°C). 

However, little success was met in the one-step synthesis of l-(2-adamantyl)-2-methyl-2-phenyl-l-ethanol from 2-chloro-2-phenylpropane, adamantanone and lithium in tetrahydrofuran [36]. But when this reaction was run in the presence of a catalytic amount (1-3 mol%) of the aromatic electron-transfer agent 4,4 -di-tm-butylbiphenyl (DBB), the desired tertiary alcohol was obtained in 67% yield ... 

Although Li-Barbier reactions had proved to be very effective to bring about syntheses of sterically crowded alcohols (see Sect. 3.3.6, pp. 86-89) little success was encountered in such a reaction with 2-chloro-2-phenylpropane and adamantone [52]. The desired product, l-(2-adamantyl)-2-methyl-2-phenyl-l-ethanol, was obtained in 67% yield, however, when l-3mol% of 4,4 di-tert-butylbiphenyl (DBB) was added as an electon-transfer agent. 

Write a mechanism for the polymerization of 2-methylpropene (isobutylene) initiated by treatment of 2-chloro-2-phenylpropane with SnCl. Label the initiation, propagation, and termination steps. 

Block copolymers of isobutene and styrene can be produced by homopolymerizing styrene in dichloromethane with titanium(IV)chloride and 2-chloro-2-phenylpropane as initiator system to a desired chain length followed by addition of isobutene [597]. At a reaction temperature of —50 °C the molecular weight of the block copolymer is = 45 000 and that of the styrene block is = 29 000. Homopolystyrene and homopoly(isobutene) are removed by extraction with pentane and butanone [598],... 

Cationic polymerization of 1,6-anhydrosugar with blocked hydroxy groups initiated by the cumyl chloride (2-chloro-2-phenylpropane)/Znl2 initiating system gave polysaccharides with relatively low dispersity 1.25). The kinetic... 

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