13e 65 111 a Unless otherwise stated the reactions were carried out at 0" C, on a 10-mmol scale of carbonyl compound with a molar ratio of Zn-Gr/bromo derivative/carbonyl compound of 15/12/10. Satisfactory analytical data (* 0.4% for C and H) were obtained for all new compounds listed in the table. Yields refer to pure compounds isolated by silica gel column chromatography with hexane-ether mixtures as the eluent. See ref 22. e The ...