phosphorus trichoride in tetrahydrofuran exclusion of air, moisture; (Ar); soln. of PCl3 in THF was dropped to soln. of (t-Bu)2PSnMe3 in THF under stirring within 30 min at -10°C (molar ratio 3:1); yellow soln. was heated to room temp.; primary yield ca. 60 P-percent; ((31)P NMR); removal of solvent at -30°C under vac.; dissolved residue in cold n-pentane; soln. was stored for 12 h at -30°C (separated Me3SnCl); removal of solvent at -30°C; purifn. of prod. with HPLC;;

T=13°C; 1) 1 h, -40 deg C, 2) 2 h, r. t.;