Synthesis of enantiopure cis-?-irone from a renewable carbon source Disclosed herein are natural and synthetic enzymes capable of performing a method of producing cis-?-irone. The method comprises providing an enzyme capable of converting psi-ionone to cis-?-irone; and contacting the enzyme and psi-ionone under suitable conditions to produce cis-?-irone. The enzyme may be a methyltransferase from Streptomyces albireticuli (SaMT), a promiscuous bifunctional methyltransferase/cyclase (pMT1) enzyme from Streptomyces, or a modified pMT1 enzyme with at least one substitution. The enzymes allow the in-vivo and in-vitro production of cis-?-irone including the use of glucose as feedstock for the biotransformation into cis-?-irone.