1-Halo-1-fluoroalkanes 4 (X= Cl, Br, I) can be straightforward prepare
d from aldehydes 1 by succcessive reaction of the corresponding gem-bi
striflates 2 with tetrabutylammonium difluorotriphenylstannate at 0-de
grees-C and then with tetrabutylammonium halides at room temperature.