24.9 (4,'JcH= 134, CH, CBr) 50.7 (d,'JcP= 150, CH, CBr) 62.7 (t,'JCH= 148, CHz [CO]) 64.4 (t,'JCH= 149,'Jcp= 7, 2 CHz [PO] 167.5 (s, C= O) analogous fluorination of tetraalkyl methanedipho~ phonates.~ However, examination of the literature reveals that several of the remaining possible halogenated PA4 esters have never been described, while for others the available synthetic procedures are not fully satisfactory. We report here detailed ...
