ethyl 1,4-dioxaspiro[4.4]nonane-9-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: A mixture of ethyl 2-oxocyclopentanecarboxylate (Aldrich, 10.0 g, 64.0 mmol), ethylene glycol (18 mL, 323 mmol), triethyl orthoformate (21 mL, 126 mmol) and p-toluenesulfonic acid monohydrate (0.61 g, 3.21 mmol) in toluene (150 mL) was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h. The mixture was cooled and poured into NaHCO3 solution, and the organic layer was separated. The aqueous layer was extracted with diethyl ether, and the combined organic layers were washed with NaCl solution and dried over Na2SO4. Filtration and concentration gave 16.41 g of 2, as a pale yellow oil, which was used in the next reaction without further purification. was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h The mixture was cooled poured into NaHCO3 solution the organic layer was separated The aqueous layer was extracted with diethyl ether the combined organic layers were washed with NaCl solution dried over Na2SO4 Filtration and concentration

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

Procedure: A mixture of ethyl 2-oxocyclopentanecarboxylate (Aldrich, 10.0 g, 64.0 mmol), ethylene glycol (18 mL, 323 mmol), triethyl orthoformate (21 mL, 126 mmol) and p-toluenesulfonic acid monohydrate (0.61 g, 3.21 mmol) in toluene (150 mL) was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h. The mixture was cooled and poured into NaHCO3 solution, and the organic layer was separated. The aqueous layer was extracted with diethyl ether, and the combined organic layers were washed with NaCl solution and dried over Na2SO4. Filtration and concentration gave 16.41 g of 2, as a pale yellow oil, which was used in the next reaction without further purification. was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h The mixture was cooled poured into NaHCO3 solution the organic layer was separated The aqueous layer was extracted with diethyl ether the combined organic layers were washed with NaCl solution dried over Na2SO4 Filtration and concentration

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

Procedure: A mixture of ethyl 2-oxocyclopentanecarboxylate (Aldrich, 10.0 g, 64.0 mmol), ethylene glycol (18 mL, 323 mmol), triethyl orthoformate (21 mL, 126 mmol) and p-toluenesulfonic acid monohydrate (0.61 g, 3.21 mmol) in toluene (150 mL) was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h. The mixture was cooled and poured into NaHCO3 solution, and the organic layer was separated. The aqueous layer was extracted with diethyl ether, and the combined organic layers were washed with NaCl solution and dried over Na2SO4. Filtration and concentration gave 16.41 g of 2, as a pale yellow oil, which was used in the next reaction without further purification. was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h The mixture was cooled poured into NaHCO3 solution the organic layer was separated The aqueous layer was extracted with diethyl ether the combined organic layers were washed with NaCl solution dried over Na2SO4 Filtration and concentration

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

Procedure: A mixture of ethyl 2-oxocyclopentanecarboxylate (Aldrich, 10.0 g, 64.0 mmol), ethylene glycol (18 mL, 323 mmol), triethyl orthoformate (21 mL, 126 mmol) and p-toluenesulfonic acid monohydrate (0.61 g, 3.21 mmol) in toluene (150 mL) was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h. The mixture was cooled and poured into NaHCO3 solution, and the organic layer was separated. The aqueous layer was extracted with diethyl ether, and the combined organic layers were washed with NaCl solution and dried over Na2SO4. Filtration and concentration gave 16.41 g of 2, as a pale yellow oil, which was used in the next reaction without further purification. was heated under reflux with removing distillate with a Dean-Stark apparatus for 1 h The mixture was cooled poured into NaHCO3 solution the organic layer was separated The aqueous layer was extracted with diethyl ether the combined organic layers were washed with NaCl solution dried over Na2SO4 Filtration and concentration