potassium hydroxide; iodine in diethyl ether; dimethyl sulfoxide addn. of NCCH2COOC2H5 to mixt. of Cr(CO)3-complex/powd. KOH in DMSO (stirring), warming (45°C, 2.5 h), diln. with aq. HCl, extn. with Et2O, treating with excess I2 (room temp., 3 h); distn. (reduced pressure);

potassium hydroxide; iodine in diethyl ether; dimethyl sulfoxide addn. of CH2(COOC2H5)2 to mixt. of Cr(CO)3-complex/powd. KOH in DMSO (stirring; 20°C, 12 h), diln. with aq. HCl, extn. with Et2O, treating with excess I2 (room temp., 3 h); distn. (reduced pressure);