dicyclohexyl-carbodiimide T=20°C; 168 h;

in methanol byproducts: N,N'-dicyclohexylurea; a soln. of B-salt and ligand in MeOH was stirred at ambient temp. for 2wk, H2O was added, mixt. extd. with CH2Cl2, dried over MgSO4; solvent was removed by rotary evaporator, dissolved in CH2Cl2, filtered, solvent was removed, vac. sublimed at 100°C;

boron trifluoride diethyl etherate Esterification;