反应详情

To a stirred solution of (R)-tert-butyl 2-(methoxy(methyl)carbamoyl)morpholine-4-carboxylate (1.37 g, 5.0 mmol) in THF (10 mL) at −20° C., there was added 1.47 M 4-methoxybutylmagnesium chloride in THF (10.2 mL, 15.0 mmol) dropwise to keep the temperature below −20° C. After addition, the resulting solution was warmed to rt and quenched with 1 N aq HCl (10 mL). The organic layer was separated, and the aqueous layer was extracted with ether (3×5 mL). Combined organic layers were washed with satd aq NaHCO3 (10 mL) and brine (5 mL) and dried over Na2SO4. Removal of the solvent under vacuum gave (R)-tert-butyl 2-(5-methoxypentanoyl)morpholine-4-carboxylate (1.41 g, 93%), which was used without purification. MS m/s 324 (M+Na+).

1. customthe temperature below −20° C
2. additionAfter addition
3. customquenched with 1 N aq HCl (10 mL)
4. customThe organic layer was separated
5. extractionthe aqueous layer was extracted with ether (3×5 mL)
6. washCombined organic layers were washed with satd aq NaHCO3 (10 mL) and brine (5 mL)
7. dry with materialdried over Na2SO4
8. customRemoval of the solvent under vacuum