1: dimethyl benzylboronate With potassium fluoride; (trifluoromethyl)-trimethylsilane in ethylene glycol dimethyl ether T=20°C; 18 h; Inert atmosphere; 2: With chloro-trimethyl-silane in ethylene glycol dimethyl ether T=-20 - -10°C; 0.333333 h; Inert atmosphere; 3: diazoacetic acid ethyl ester With methanol in ethylene glycol dimethyl ether T=-20 - 20°C; 2 h; Inert atmosphere;

in tetrahydrofuran; diethyl ether; hexane byproducts: LiCl; to a soln. of LiCHCl2 (THF, hexane) boronic ester in diethyl ether was added at -100°C in one portion, the soln. was allowed to warm slowly to 20-25°C and kept overnight, Ar atm.; CH2Cl2 was added to precipitate LiCl, filtration, evapn. in vac., distn.; elem. anal.;