Water → Methyl 17-oxocycloheptadec-8-ene-1-carboxylate

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Reaction Steps

Under an argon stream, CH2Cl2 solvent (0.5 ml) was placed in a two-necked flask beforehand, and thereto were added dropwise, at 0 to 5° C., a mixed solution of dimethyl cis-9-octadecenedioate (170 mg, 0.50 mmol) and Et3N (152 mg, 1.50 mmol) in CH2Cl2 (2.15 ml) and a solution of TiCl4 (159 μl 1.45 mmol) in CH2Cl2 (2.45 ml) at the same time over a period of about 1 hour by means of a microfeeder. The whole was further mixed at the same temperature for 15 minutes. Water was added to the reaction mixture and the resulting mixture was stirred and then extracted with ether. The organic layer was washed with water and saturated brine, and then dried over anhydrous sodium sulfate. After the evaporation of the solvent under reduced pressure, the crude product was purified by silica gel chromatography (hexane/ethyl acetate=20/1→10/1) to obtain the aimed product (83 mg, 54%) and a by-product (34-membered ring; 21 mg, 14%).

Provenance & Evidence