Isolated literature precedent was found for similar reactions: 3, 4-dihydro-2H-pyran (3b) reacts with 3-hydroxy-2-cyclohexen-1-one (5c) in the presence of catalytic sulfuric acid to afford a modest yield of 2-Chlorotetrahydropyran reacts similarly with 3-hydroxy-2- cyclohexen-1-one (5c) to give a lower yield of 7c. However, yields from 2- chlorotetrahydrofuran are dismal, and acyclic@-diketones and 3-hydroxy-2-cyclopenten-1 ...
