in pentane byproducts: (CH3)3SnCl; condensation of B-compd. into a soln. of (Me3Sn)2O in pentane at -196°C under N2, warming to room temp.; removal of volatile compds., sepn. of volatile compds. into product and solvent fractions at -78°C and -196°C, respectively, further sepn. yields (MeBO)3 and further B-compd. at -40°C, at-25°C oxadiborinane;

in pentane byproducts: (CH3)3SnCl; stirring B-compd. and SnMe4 in pentane at -78°C under N2, slow warming to room temp., rapid cooling to -78°C, pptn. of Me3SnCl,; fractionated condensation at -30°C, -78°C and -196°C, condensation at -20°C (5-10 times) to remove Me3SnCl;

in pentane byproducts: Me3SiCl; slow warming B-compd. and (Me3Si)2NMe in pentane to room temp. (under N2); monitoring by (11)B-NMR, fractionated condensation in vacuo;

in pentane byproducts: (CH3)3SnCl; condensation of B-compd. into a soln. of (Me3Sn)2O in pentane at -196°C under N2, warming to room temp.; removal of volatile compds., sepn. of volatile compds. into product and solvent fractions at -78°C and -196°C, respectively, further sepn. yields (MeBO)3 and further B-compd. at -40°C, at-25°C oxadiborinane;