A. Reaction with Bis (dihydroxyphosphinomet hy1)-phosphinic Acid (10).(i) Acid 10 (24 mg, 0.09 mmol), tri-noctylamine (95 mg, 0.27 mmol), and 5'-O-tosylthymidine (12 mg, 0.03 mmol) were heated in DMF (0.3 mL) in a closed tube at 120 “C. No substantial darkening occurred. Samples were taken at 2.5 and 4 h.(ii) The procedure was the same as in (i), but with 02, 5'- cyclothymidine17 (13; 7 mg, 0.03 mmol) in place of 4. The solution darkened within a few ...
