Sulfuric Acid → bis[(Z)-3-hexenyl]oxalate

Reaction equation

[C:1](Cl)(=[O:5])[C:2](Cl)=[O:3].[CH2:7]([OH:13])[CH2:8]/[CH:9]=[CH:10]\[CH2:11][CH3:12].OS(O)(=O)=O>N1C=CC=CC=1>[CH2:7]([O:13][C:1](=[O:5])[C:2]([O:13][CH2:7][CH2:8]/[CH:9]=[CH:10]\[CH2:11][CH3:12])=[O:3])[CH2:8]/[CH:9]=[CH:10]\[CH2:11][CH3:12]

Participants

Procedure

Oxalyl chloride (12.7 g, 100.0 mmol) was added dropwise during 20 min to a stirred solution of (Z)-3-hexenol (20.0 g, 200.0 mmol) in pyridine (240 mL) at 0° C. The reaction mixture was allowed to warm up to room temperature during the week-end, then added to H2SO4 (50%, containing ice, 400 mL), extracted with ether (400 mL and 200 mL), treated again with H2SO4 (50%, containing ice, 400 mL), washed with a saturated solution of NaCl (200 mL) and a saturated solution of NaHCO3 (200 mL, 2×). The organic layer was dried (Na2SO4) and concentrated. Column chromatography (SiO2, heptane/diethyl ether 9:1) gave, after drying under vacuum (0.5 mbar, 1 h), 20.9 g (82%) of an oil.