in tetrahydrofuran addn. of equimolar amount of cyclopropene to soln. of K salt in THF under N2;; evapn. to dryness; addn. of toluene; filtration; concn.; chromy. (silica, toluene: isolation of Cr arenes, then ether: isolation of Cr carbene);;

in tetrahydrofuran byproducts: NaCl; Addn. of Cl2C(C(t-Bu)C(t-Bu)) soln. to soln. of Mn-complex at room temp. under N2, color changes immediately to orange red.; Evapn. of solvent, dissolving in toluene, column chromy. (SiO2, 5°C, toluene), evapn. of the second zone in vac., recrystn. (pentane, -78°C), elem. anal.;

in tetrahydrofuran addn. of equimolar amount of cyclopropene to soln. of K salt in THF under N2;; evapn. to dryness; addn. of toluene; filtration; concn.; chromy. (silica, toluene: isolation of Cr arenes, ether: isolation of Cr carbene);;