反应详情

(R)—((S)-2-(3,5-dichloropyridin-4-yl)-1-(3,4-dimethoxyphenyl)ethyl) 2-(6-methoxynaphthalen-2-yl)propanoate (30 g, 56 mmol) was dissolved in MeOH, and toluene was slowly added. Potassium terbutoxide was slowly added to the suspension. The mixture was stirred for 24 hours at RT. The reaction was diluted with water (500 ml), and the aqueous mixture was extracted with CHCl3 (500 ml). The organic layer was dried over Na2SO4 and the solvent was evaporated under vacuum. The residue was crystallized from CHCl3 (100 ml) and hexane (20 ml). The mother liquor was concentrated and recrystallized with an analogous procedure giving a second crop of desired compound. In total, 16 g of the title compound (87% yield) were obtained. Chiral HPLC analysis Rt=58.03 min; eluent:hexane:isopropanol=95:5; [α]D20=+10.21 (c=0.506, Methanol); 1H NMR (400 MHz, acetone) δ ppm 8.47 (s, 2H), 6.96-7.15 (m, 1H), 6.87 (m, 2H), 4.93-5.21 (m, 1H), 4.50 (d, J=3.97 Hz, 1H), 3.78 (s, 6H), 3.44 (dd, J=12.79, 8.38 Hz, 1H), 3.22 (dd, J=13.01, 5.51 Hz, 1H). MS/ESI+ [MH]+: 328.19

1. extractionthe aqueous mixture was extracted with CHCl3 (500 ml)
2. dry with materialThe organic layer was dried over Na2SO4
3. customthe solvent was evaporated under vacuum
4. customThe residue was crystallized from CHCl3 (100 ml) and hexane (20 ml)
5. concentrationThe mother liquor was concentrated
6. customrecrystallized with an analogous procedure