in tetrahydrofuran react. under N2; THF cooled to -60°C, addn. of borate and Grignard reagent in THF simultaneously (equimolar amts. over whole period of react.), then stirred for 30 min at -60°C, warmed to room temp., stirred for 30 min;; treated with water, extd. with Et2O, organic layers extd. with 1M aq. NaOH, aq. layers acidified with 2M aq. HCl, extd. with CH2Cl2, organic layers dried (MgSO4), filtered, concentrated, recrystd. from water; elem. anal.;;

methylmagnesium bromide; NiCl2((PPh3)P)2 in diethyl ether; benzene Heating;