Aliphatic reactions with boron-stabilized carbanions

It was early reported that boron-stabilized carbanions reacted with benzaldehyde and ketones to yield alkenes (equation 40). The reaction gave a 45-50% yield in the one case quantified, with ( ) (Z) ratios varying over a wide range with temperature. Benzophenone gave a similar yield but the yields with aliphatic ketones were considerably less. °... 

P-Keto esters have been prepared in moderate to high yields by treatment of aldehydes with diethyl diazoacetate in the presence of a catalytic amount of a Lewis acid such as SnCL, BF3, or GeCL. The reaction was successful for both aliphatic and aromatic aldehydes, but the former react more rapidly than the latter, and the difference is great enough to allow selective reactivity. In a similar process, aldehydes react with certain carbanions stabilized by boron, in the presence of (F3CC0)20 or NCS, to give ketones. 

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