Synthesis of (R)-(+)-4-methylcyclohex-2-ene-1-one.

A three-step synthesis of (R)-(+)-4-methylcyclohex-2-ene-1-one (1) from (R)-(+)-pulegone (3), proceeding in 44% overall yield, is described. The sequence comprises vinyl triflate formation, site-selective ozonolysis, and reduction. The route requires only one chromatographic purification and provides a convenient method to access multigram quantities of (R)-(+)-4-methylcyclohex-2-ene-1-one (1).