“…The solvent was removed and the crude product was recrystallized from toluene to give 5 (5.68 g, 63%) as a white powder. Mp 120-122°C; [1,4,7,10,13,16] pentaoxa-k 5 -phosphacyclooctadecin-22-one (S,S)-8. Tetraethylene glycol ditosylate (S,S)-7 2 (1.00 g, 1.28 mmol), ethyl phosphinate 5 (0.50 g, 1.28 mmol), and finely powdered anhydrous K 2 CO 3 (2.00 g) were mixed with vigorous stirring in dry DMF (30 mL) under argon.…”