1,2,3,4-tetrachloro-5,5-dimethoxycyclopenta-1,3-diene

Conditions: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.07 g of 5,5-dimethoxy-1,2,3,4-tetrachlorocyclopenta-1,3-diene, 0.34 g of sodium hydrogen carbonate, 0.50g of trans-1-(3-methylisoxazol-5-yl)-1-propene and 0.05 g of hydroquinone were mixed and heated with stirring at 180° C. for 7 hours. The reaction solution was cooled and ethyl acetate was added. Insoluble matter was removed by filtration. Then the solvent was concentrated under reduced pressure. The obtained crude product was purified on silica gel column chromatography (elution with benzene) to give 0.70 g of the title compound as a mixture of isomers. heated The reaction solution was cooled Insoluble matter was removed by filtration Then the solvent was concentrated under reduced pressure The obtained crude product was purified on silica gel column chromatography (elution with benzene)

Conditions: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.07 g of 5,5-dimethoxy-1,2,3,4-tetrachlorocyclopenta-1,3-diene, 0.34 g of sodium hydrogen carbonate, 0.50g of trans-1-(3-methylisoxazol-5-yl)-1-propene and 0.05 g of hydroquinone were mixed and heated with stirring at 180° C. for 7 hours. The reaction solution was cooled and ethyl acetate was added. Insoluble matter was removed by filtration. Then the solvent was concentrated under reduced pressure. The obtained crude product was purified on silica gel column chromatography (elution with benzene) to give 0.70 g of the title compound as a mixture of isomers. heated The reaction solution was cooled Insoluble matter was removed by filtration Then the solvent was concentrated under reduced pressure The obtained crude product was purified on silica gel column chromatography (elution with benzene)

Conditions: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.07 g of 5,5-dimethoxy-1,2,3,4-tetrachlorocyclopenta-1,3-diene, 0.34 g of sodium hydrogen carbonate, 0.50g of trans-1-(3-methylisoxazol-5-yl)-1-propene and 0.05 g of hydroquinone were mixed and heated with stirring at 180° C. for 7 hours. The reaction solution was cooled and ethyl acetate was added. Insoluble matter was removed by filtration. Then the solvent was concentrated under reduced pressure. The obtained crude product was purified on silica gel column chromatography (elution with benzene) to give 0.70 g of the title compound as a mixture of isomers. heated The reaction solution was cooled Insoluble matter was removed by filtration Then the solvent was concentrated under reduced pressure The obtained crude product was purified on silica gel column chromatography (elution with benzene)

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 500 mL 3N RB flask equipped with a water condenser, N2 flow adapter and thermometer, was placed 5,5-dimethoxy-1,2,3,4-tetrachlorocyclopentadiene (20.7 g, 0.078 mol) and vinylene carbonate (6.7 g, 0.078 mol). The mixture was heated to 90° C. for 4 h, then at 60° C. for 63 h. The reaction was judged complete by TLC and upon cooling, the product solidified, was recrystallized from THF and filtered to provide a white solid (25.80 g, 94%). (TLC 20% EtOAc/hexanes Rf 0.29); 1H NMR (400 MHz, CDCl3) δ 5.13 (s, 2H), 3.59 (s, 3H), 3.56 (s, 3H); GCMS m/z 348 (M)+; mp 160–162° C.; Anal. Calcd. for C10H8Cl4O5: C, 34.32; H, 2.30. Found C, 34.32; H, 2.27. In a 500 mL 3N RB flask equipped with a water condenser, N2 flow adapter upon cooling was recrystallized from THF filtered

Conditions: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.07 g of 5,5-dimethoxy-1,2,3,4-tetrachlorocyclopenta-1,3-diene, 0.34 g of sodium hydrogen carbonate, 0.50g of trans-1-(3-methylisoxazol-5-yl)-1-propene and 0.05 g of hydroquinone were mixed and heated with stirring at 180° C. for 7 hours. The reaction solution was cooled and ethyl acetate was added. Insoluble matter was removed by filtration. Then the solvent was concentrated under reduced pressure. The obtained crude product was purified on silica gel column chromatography (elution with benzene) to give 0.70 g of the title compound as a mixture of isomers. heated The reaction solution was cooled Insoluble matter was removed by filtration Then the solvent was concentrated under reduced pressure The obtained crude product was purified on silica gel column chromatography (elution with benzene)