in diethyl ether Ar-atmosphere; mixing at -50°C, warming to room temp. (during 2 h); evapn. (vac., room temp.), toluene addn. filtration off of Li-triflate, evapn. (vac.); elem. anal.;

in diethyl ether Ar-atmosphere; mixing at -50°C, warming to room temp. (during 2 h); evapn. (vac., room temp.), toluene addn. filtration off of Li-triflate, evapn. (vac.); elem. anal.;

in diethyl ether Ar-atmosphere; mixing at -50°C, warming to room temp. (during 2 h); evapn. (vac., room temp.), toluene addn. filtration off of Li-triflate, evapn. (vac.); elem. anal.;