Toluene → Diethylphosphite

Participants

Reaction Steps

Compound Spinosyn H (351 mg, 0.489 mmol) was dissolved in dry pyridine (5 ml). DMAP (62 mg, 0.51 mmol) was added and stirring at RT under nitrogen was continued for 5 min. Diethyl chlorophosphite (157 mg, 0.145 ml, 1.0 mmol) was added. After 30 min. toluene (50 ml) and EtOAc (50 ml) were added. The solution was washed successively with brine (2×) and 5% aq. NaHCO3. The organic layer was dried over Na2SO4 and concentrated. The residue was separated over a flash SiO2 column (100 g/EtOAc) to give compound 2'R)-(diethyl)phosphite of Spinosyn H; 306 mg, 75% CI MS m/z 838 (M+1); 1H-NMR (CDCl3) δ 6.69 (1H, bs), 4.40 (1H, m), 3.83 (4H, 2× CH2, m), 1.18 (6H, 2× CH3, m); Elemental Analysis: for C44H72NO12P calc. C 63.06, H 8.66, N 1.67 found: C 62.94, H 8.88, N 1.71.

Provenance & Evidence