反应详情

Oxalyl chloride (2.9 mL, 34 mmol) was added dropwise to a −78° C. solution of dimethyl sulfoxide (2.9 mL, 41 mmol) in CH2Cl2 (40 mL). Stirring was continued at −78° C. for an additional 10 min prior to the slow introduction down the flask wall of a solution of ethyl 3-{2-[(benzyloxy)methyl]-4,4-difluorocyclohexyl}-3-hydroxy-2-[4-(methylthio)phenyl]propanoate (5.09 g, 10.6 mmol) and triethylamine (16 mL, 120 mmol) in CH2Cl2 (40 mL). The mixture was then held at −78° C. for 10 min followed by rapid warming to rt before being poured into 2 M HCl in a separatory funnel. The layers were shaken and separated, and the aqueous phase was extracted with an additional portion of CH2Cl2. The combined organics were washed with water, dried (Na2SO4) and concentrated. Flash chromatography of the residue on silica gel eluting with 1/4 ethyl acetate/hexanes afforded ethyl 3-{2-[(benzyloxy)methyl]-4,4-difluorocyclohexyl}-2-[4-(methylthio)phenyl]-3-oxopropanoate as a thick, tan colored syrup.

1. waitThe mixture was then held at −78° C. for 10 min
2. stirringThe layers were shaken
3. customseparated
4. extractionthe aqueous phase was extracted with an additional portion of CH2Cl2
5. washThe combined organics were washed with water
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated