A new and efficient route to derivatives of (R)-4-hydroxycyclohex-2-enone

A new and efficient route has been developed to four derivatives of (R)-4-hydroxycyclohex-2-enone (7–10) from one intermediate, 6. These derivatives are useful chiral building blocks in the synthesis of natural products and in asymmetric reactions. The key step is a stereoselective intramolecular ene reaction with 4 Å MS as the Lewis acid and catalyst.