William G. Young

Nuclear magnetic resonance and 203Hg exchange studies of allylmercury systems: A comment on allylmercuric perchlorate

Abstract Nuclear magnetic resonance data for allyl-, β-methallyl-, crotyl- and cinnamylmercuric halides and acetates are presented and the dramatic effect of added mercuric salts on some of these spectra is discussed. The exchange of mercury between allyl- and β-methallylmercuric halides (chloride or bromide) and the appropriate mercury-(II) halide, utilising 203Hg as a tracer, is very rapid (statistical exchange in less than a minute at 20°) and appears to be one of the fastest organic-inorganic HgII exchanges reported. Mechanisms of the SEi′ variety are suggested, and the significance of the exchange in relation to the effect of HgII halides on the PMR spectra of allylmercury systems is pointed out. The preparation and some properties of a compound argued to be allylmercuric perchlorate are presented.

The Butenes from the Reduction of Isobutyraldehyde by s-Butylmagnesium Bromide

Whitmore and George have shown that the reduction of diisopropyl ketone by a Grignard reagent involves hydrogen atoms attached to the beta-carbon atom of the Grignard reagent. If the Grignard reagent had no hydrogen atoms on the β-carbon, as with neopentylmagnesium chloride, no reduction was detected. It was pointed out that a correlation exists between the extent of reduction of diisopropyl ketone and the number and primary, secondary or tertiary character of the β-hydrogens of the Grignard reagents. It is difficult, however, to determine the relative reduction rates of the different classes of β-hydrogen atoms from data obtained with several Grignard reagents because the competing reactions of addition and enolization are also markedly influenced by structure.