Schmidt reaction migratory aptitudes

Other work in which migratory aptitudes have been compared has involved the formation of the azide (or its conjugate acid) in situ from the corresponding alcohol or olefin, and its decomposition without isolation (the Schmidt reaction). For example, 1-substituted cyclohexanols underwent predominantly ring expansion when the 1-substituent was methyl, ethyl or cyclohexyT. A series of tertiary carbinols were studied in which it was found that the migration tendency was in the order Ph i-Pr CgHii Et The products of... 

The Schmidt reaction of diarylmethylcarbinols or 1,1-diarylethy-lenes and benzhydrols, or acid-catalysed decomposition of 1,1-diarylethyl azides or benzhydryl azides has received considerable attention, and reliable data are available. It was found that a Hammett relationship was followed in the migratory aptitudes of substituted aryl groups. For the Schmidt reaction of unsymmetrical 1,1-diarylethylenes, the Hammett relationship was " ... 

Several types of Schmidt reaction merit special mention (a) An interesting consequence of the factors governing migratory aptitudes is that acetanilides are the major (typically >95%) products of rearrangement of acetophenones. This leads to a practical alternative to nitration and reduction as a preparative route to aromatic amines , cf. reaction (24). (b) Product analyses showed that... 

An investigation into the migratory aptitudes of C-2 versus C-4 in Beckmann, Schmidt, and Baeyer-Villiger reactions employed 13C n.m.r. spectroscopy and demonstrated that all reactions proceeded with migration of both C-2 and C-4... 

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