in diethyl ether byproducts: (CF3(CF2)5CH2CH2)2; a soln. of Sn-compound added to a soln. of Grignard compound; hydrolyzed with NH4Cl soln.; washed with 5percent Na2S2O3 soln. and water; dried; evapd.; chromy.;

chlorine in methanol an ice-cooled suspn. of Sn-compound titrated with an excess of Cl2 in methanol; evapd.; recrystd. from n-hexane;