Sulfuric Acid → 3-Oxaspiro[5.5]undec-7-en-9-one

Participants

Reaction Steps

0.5 ml of sulphuric acid is added to 317 mmol of tetrahydro-2H-pyran-4-carboxaldehyde and 317 mmol of methyl vinyl ketone in 500 ml of benzene. The reaction mixture is then refluxed for 3 hours, water being removed using a Dean-Stark apparatus, and then a further 317 mmol of methyl vinyl ketone are added and reflux is continued for 3 hours. The mixture is subsequently washed, dried and then concentrated, and the residue obtained is distilled to yield the expected product.

Provenance & Evidence