Solid reaction enantiospecificity

Many of the above-described examples highlight the diastereoselectivity of the solid-state reaction. Cyclic ketones with cis- or trans-a,a -substituents give the ring-contraction product with the same relative stereochemistry. Examples include 2-indanones 157 and 159 (Scheme 2.38), cyclohexanones 162 and 164—167 in Scheme 2.39, and ketones 177 and 179 in Scheme 2.43. The diastereospedfidty and enantiospecificity of linear ketones was also tested with the pentasubstituted acetone derivative 187 in its racemic and enantiomerically pure forms (Scheme 2.45). Notably, both samples reacted efficiently and in a completely diastereo-specific manner when reactions were carried out to 60% conversion. Sample of ( I )-(2R,4S)-187 gave the corresponding combination product in 100% ee and... 

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