in hexane byproducts: LiCl; under Ar, dropwise addn. of Li-compd. in hexane within 2 h to a hexane soln. of borane, stirred for 16 h at room temp.; centrifuged, distn. of volatiles in vac., taken up in hexane, cooled to -78°C for 48 h, isolation at -78°C, washed with hexane (-78°C); elem. anal.;