(18) A referee has suggested that the results with the methyl halide Grignard reagents which show yields of 4cw in the order I< Br< CI (and the high yield of 4cw with dimethylmagnesium) may be indicative of a single electron transfer mechanism. He suggests further that the effect of ferric chloride may also indicate a SET mechanism and wonders what the reaction with the tert-butyl chloride Grignard reaction might reveal. ...