In a 1L four neck flask, which was fitted with a mechanical stirre, thermometer, reflux condencer and a dropping funnel, to a mixture of trimethoxyphsphite (100mmol) and toluene (350ml), methyliodidte (110mmol) was added with stirreing for 15min under 50 deg. Then it was refluxed over night. The reaction mixture was cooled to r.t. and concentrated in vacuo. The resulting residue was distillated (at deg, mmHg, 87%).