Small-Ring Compounds. XLVII. Reactions of Optically Active Cyclopropylmethylcarbinyl Derivatives1,2a

Abstract

Cyclopropylmethylcarbinylamine and cyclopropylmethylcarbinol were resolved into optical antipodes and their configurations were related. The former was deaminated with aqueous nitrous acid to give the latter with 0-4% net inversion of configuration. Solvolysis of N-methyl-4- alkoxypyridinium salts was investigated as a means of providing a leaving group which would not undergo “internal return.” Solvolysis rates for N-methyl-4-(cyclopropylcarbinyloxy)pyridinium iodide and perchlorate in water and in 80% ethanol and of N-methyl-4-(cyclopropylmethylcarbinyloxy)pyridinium iodide in water were measured. The first-order rate constant for the hydrolysis of N-methyl-4-(cyclopropylmethylcarbinyloxy)pyridinium iodide at 30o was calculated to be 6 x 10^3 times that of N-methyl- 4-(cyclopropyIcarbinyloxy)pyridinium iodide. The hydrolysis of optically active N-methyl4-(cyclopropylmethylcarbinyloxy) pyridinium iodide produced cyclopropylmethylcarbinol with 4.4 ± 1.5% inversion of configuration. The stereochemistry of the deamination of cyclopropylmethylcarbinylamine and of the hydrolysis of Nmethyl-4-(cyclopropylmethylcarbinyloxy)pyridinium iodide and the ratio of rate constants for the cyclopropylmethylcarbinyl and cyclopropylcarbinyl pyridinium salts are discussed with respect to the possible intervention of nonclassical carbonium ion intermediates in these reactions.