methyl iodide in tetrahydrofuran; hexane addn. of BuLi-soln. in hexane to W-complex in THF, stirring for 1 h; react. under inert atmosphere; evapn. (vacuum), column chromy. (hexane), monitored by IR and NMR;

methyl iodide in tetrahydrofuran; hexane addn. of BuLi-soln. in hexane to W-complex in THF, stirring for 1 h; react. under inert atmosphere; evapn. (vacuum), column chromy. (elution with hexane), react. monitored by IR and NMR;

diethyl ether