" C) led principally to 5, but at higher temperatures to 3-methyl-2-butanone (9) via a pinacol- pinacolone type rearrangement involving the intermediates 2, 2-dimethyl-3-oxobutanamide (10) and 2, 2-dimethyl-3-oxobutanoic acid (111, which decarboxylates spontaneously to 9. In the acid hydrolysis of 2 to obtain 5 and 6 directly, substantial amounts of the byproduct 2- hydroxy-2, 3-dimethyl-3-butenoic acid (12) were encountered; better yields of the desired ...