Lithiated dimethylhydrazone crystal structure

The azaallyl oidates, Le. enolates derived from ketone imines or hydrazones are synthetic equivalents of the ketone endates and thus two examples of azaallyl enolates are included in th section. Lithiated cyclrdiexanonephenylimine (151) crystallizes out of hydrocarbon solution as the dimeric diisopropylamine solvate (152). Significant disorder between the cyclohexyl and the phoiyl moieties is obse ed in this crystal structure however, it is clear that there are no V-az yl carbm contacts in this structure. This lithiated imine structure can be compared with the lithittted dimethylhydrazone of cyclohexanone... 

The sodium salt of the stabilized enolate derived from the heteroaryl-substituted 2-oxoglutaric acid ester (186) is reported to have the alkene geometry as shown in formula (187). Hnally, Collum et al. have reported the structure of the lithiated anion derived from the A, A -dimethylhydrazone of 2-methoxy-carbonylcyclohexanone (188). This enolate crystallizes as the dimeric, bis-THF-solvated aggregate (189). 

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