Triethylamine → 3-[5-(2-Methyl-[1,3]dioxolan-2-yl)-pentanoyl]-oxazolidin-2-one

Temperatur

0 °C

To a stirred solution of 2-2 (16.0 g, 85.5 mmol), NEt3 (13.1 ml, 94.1 mmol) and THF (400 mL) at −78° C. was added pivaloyl chloride (11.6 ml, 94.1 mmol). The mixture was warmed to 0° C. for 1.0 h and then recooled to −78° C. To a stirred solution of 2-oxazolidinone (9.3 g, 106.9 mmol) and THF (200 ml) at −78° C. was added nBuLi (43.0 ml, 106.9 mmol, 2.5M in hexanes) dropwise over 10 minutes. After 20 minutes, the lithium reagent was transferred to the mixed anhydride via cannula. After 10 minutes, the reaction was warmed to 0° C. for 1.0 h. The mixture was diluted with ethyl acetate, washed with sat. NaHCO3, brine, and dried over MgSO4. Following evaporative removal of the solvent, the residue was chromatographed (silica gel, 40%-50% EtOAc/hexanes) to give 2-3 as a colorless foam.

1. customrecooled to −78° C
2. waitAfter 10 minutes
3. temperaturethe reaction was warmed to 0° C. for 1.0 h
4. washwashed with sat. NaHCO3, brine
5. dry with materialdried over MgSO4
6. customremoval of the solvent
7. customthe residue was chromatographed (silica gel, 40%-50% EtOAc/hexanes)

ORD-Eintrag

ord-ba4689a5c6be4bc5ad66c4444783f98b

Quelldatensatz

uspto-grants-2001_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06211191B1