ethanol in dichloromethane; pentane under N2; to soln. of B complex in CH2Cl2 added pentane cooled to -10 °C, slowly added alcohol, stirred for 15 min; upper layer sepd., lower layer extd. with cold (0 °C) pentane, combined ext. evapd. in vac., distd.;

ethanol in pentane under N2; to suspn. of boronic acid in pentane added EtOH in separatoryfunnel, shook for few s, H2O removed, EtOH added, shook for few s; H2O layer removed, org. layer dried with MgSO4, solvents evapd., distd.;