Chloroform → 1-oxoheptyl-D-allo-Threonine

A solution of n-heptanoyl chloride (440 mL, 2.83 mmol) in THF (250 mL) is added dropwise, over a period of 30 min, to a cold (-5 to 0° C., vigorously stirred mixture of D-allo-Thr (300 mg, 2.51 mmol) and 2N aq. NaOH (3.5 mL, 7.0 meq) in THF (4.0 mL). The resulting mixture is stirred for 2 h at the same temperature and overnight at room temperature. The volatiles are removed and the residue is diluted with o water and acidified, using conc. HCl. The mixture is extracted with EtOAc and the combined organic solution is washed with brine, dried, filtered, and concentrated to provide crude 2c-1 (420 mg, containing 10% excess heptanoyl reagent) which solidifies upon standing. NMR δ1.28 (d, J=6.5, 3H), 4.20 (m, 1H), 4.61 (dd, J=3.4, 6.6, 1H), 6.56 (br d, J=6.9, 1H); [α]D26 -38±2 (CHCl3).

1. customThe volatiles are removed
2. additionthe residue is diluted with o water
3. extractionThe mixture is extracted with EtOAc
4. washthe combined organic solution is washed with brine
5. customdried
6. filtrationfiltered
7. concentrationconcentrated
8. customto provide crude
9. addition2c-1 (420 mg, containing 10% excess heptanoyl reagent) which

ORD-Eintrag

ord-5ab5a13c555447ac968b5125ae1618d8

Quelldatensatz

uspto-grants-1994_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05312831