Opening reactions with nitriles

Epoxides also participate in the Ritter reaction with nitriles. An investigation of the ring opening of several alkyl-substituted glycidic esters and amides 181 showed that this transformation occurs with inversion and is completely regiospecific. ° Esters appeared to be somewhat more reactive than amides. However, phenyl-substituted glycidic esters and amides 184 are almost totally nonstereoselective. In addition, the oxazolines 186 are isolated in low yield due to the propensity of intermediate 185 to generate an aldehyde byproduct 187 (Scheme 8.53). 

The reaction with nitrile oxides 33 gave open-chain isoxazoles 34 because of p-elimination of the ring ojgrgen following cycloaddition (Scheme 10). ... 

Machiguchi, Nozoe and coworkers have very recently observed that in contrast to chemical reactivity of tropones, the tosylate of tropone oxime undergoes a facile ring-opening to 6-substituted (Z,Z,Z)-1,3,5-hexatriene nitriles on reaction with various nucleophiles305. For example, reaction of phenyl lithium results in the corresponding hexatriene carbonitrile (equation 183). 

Dipolar cycloaddition of C60 with nitrile oxides was modeled at the B3LYP/6-31G(d,p)//AMl level, and its mechanism and regiochemistry were investigated. Theoretically, the reaction can proceed by four types of additions, viz., closed [6,6], open [5,6], closed [5,6], and open [6,6] additions. Analysis of... 

The cyanobromide (371) was condensed with the bc portion (347) to give the thioether (372) sulfide contraction to give (373) was accomplished using tris(/3-cyanoethyl) phosphine, and with phosphorus pentasulfide the thiolactam-thiolactone (374) was produced. After treatment with Meerwein s salt, reaction with dimethylamine opened the lactone with concomitant formation of an exocyclic methylene group, and subsequent treatment with cobalt chloride or iodide gave the chelate (375) which was reacted with diazabicyclononane to give bisnorcobyrinic add [Pg.435]

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