Pivalamide derivatives

A related mechanism is almost certainly observed in the almost instantaneous metha-nolysis of some pivalamide derivatives in the presence of copper(n) chloride. For example, ligand 5.34 forms a five co-ordinate complex with copper(n) chloride. When... 

This rearrangement proceeds via a bicyclic acetal (e.g., 30), and therefore it is a double isomerization involving a ring expansion followed by a ring contraction. It was shown to be most effective using benzamide or pivalamide derivates and the ratio of the ester to the bicyclic acetal was dependent on the reaction conditions used for example, with 5mol% of MeOTf at 130 °C in chlorobenzene, 53% of 29 and 14% of 30 was formed. 

Figure 22-25. Structure of pivalamide derivative of l-(l-naphthyl)ethylamine. (Reprinted from reference 99, with permission.)...

Ge and coworkers developed Cu(OAc)2-catalyzed intramolecular amidation of A/ -(quinolin-8-yl)pivalamide derivatives to mono-, spiro-, and bicyclic -lactam... 

Non-enolizable aliphatic ketones are cleaved analogously. For example, pivalamide and isobutane are formed in good yield from hexamethylacetone (2,2,4,4-tetramethyl-3-pentanone). Most unsymmetrically substituted ketones afford the four possible products (2 amides and 2 hydrocarbons), but often in unequal amounts, e.g., pivalamide and 2,2-diethylbutyramide in 5 1 proportions from 4,4-diethyl-2,2-dimethyl-3-hexanone. Hexaalkyl-substituted acetone derivatives containing branched alkyl groups generally do not react. 

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