Cyclohexyl chloride Grignard reagent from

The effect of the leaving group was briefly examined, but cinnamyl bromide gave a substantially lower ee (38%). Cinnamyl dimethyl phosphonate, or acetate, gave very poor results. The cyclohexyl-substituted allylic acetate 21, on the other hand, afforded a completely y-selective reaction, but the product turned out to be racemic. Changing the Grignard reagent halide from bromide to either chloride or iodide resulted in very low ees. 

Figure 2 Four representative Grignard reagents plotted according to Eq. (5) cyclohexyl bromide vs. cyclopentyl bromide ( ) cyclopentyl chloride vs. cyclopentyl bromide (A) n-pentyl chloride vs. cyclohexyl chloride ( ) neopentyl bromide vs. cyclopentyl bromide (O)- (From Ref. 81b.)...

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