Ethylzinc enolate, structure

Enantiomerically pure and racemic / -carbonyl sulfoximes were treated with diethylzinc to afford the corresponding ethylzinc enolates 148a-c in both racemic and optically active forms (Scheme 94).214 Despite their rather similar solution structures, these complexes exhibited markedly different solid-state structures and reactivities with electrophiles. 

Three ethylzinc enolates containing a tertiary nitrogen atom in -position to the enolate oxygen atom have been prepared and were structurally characterized by X-ray crystallography. The structures of these compounds are shown schematically in Figure 85. 

No crystallographic structure has been reported for zinc ketone enolates. Although carbon-bonded structures analogous to (5) have been proposed, spectral data obtained for the bromozinc and ethylzinc... 

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