Ketone lithium enolates solid state

SCHEME 59. Various types of solid-state mixed aggregates involving ketone lithium enolates (A) pinacolone enolate/lithium amide [LiHMDS/CH2C(OLi)Bu-i, 2 DME]230 (B) pentan-3-one enolate/2 chiral lithium amide232 (C) pinacolone enolate/lithium amide/LiBr [LiHMDS/2 Cl HCtOI.ijBu-f/LiBr, 2 TMEDA]235... 

Lithium enolates of ketones exist as aggregates in solution.29-3l,34d,35 Mixed aggregates between the enolate anion and the amide base are also possible. In 1981, Seebach and co-workers confirmed by X-ray crystallography that the lithium enolates of pinacolone and cyclopentanone form a tetrameric aggregate in the solid state, and it was assumed that a similar species exited in solution. A THF solvated tetramer of lithium pinacolonate is shown (see 33), as it was reported by Seebach. Williard et al. reported the X-ray structure of... 

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