Benzene → Methyl 1,4-dioxaspiro[4.5]decane-8-carboxylate

Participants

Reaction Steps

A mixture of 189.7 g. of 4-carbomethoxy-1-cyclohexanone [3] (obtained as in Example 2B) in 2000 ml. of benzene, 67.5 ml. of ethylene glycol and 2.7 g. of p-toluenesulfonic acid is heated at reflux under a Dean-Stark trap for about 5 hours. After cooling, the solution is washed with saturated aqueous sodium bicarbonate and brine. The oily residue remaining when the organic solvent is evaporated to dryness and is distilled under vacuum to give 231.8 g. of 4-carbomethoxy-1-cyclohexanone ethylene ketal[4] having a boiling point of 95° to 100° C. at 0.30 mm. of Hg.

Provenance & Evidence