Synthesis of Racemic (E)- and (Z)-2,3-Methanotyrosine: New Cyclopropane Analogues of Tyrosine

Article abstract of DOI:10.1021/jo00262a033

Both (E)- and (Z)-2,3-methanotyrosine <(E)-2,3-MeTyr and (Z)-2,3-MeTyr> have been synthesized from the monoester 5, which was prepared by cyclopropanation of the benzalmalonate 3, followed by regioselective saponification and Curtius rearrangements to introduce the amino group stereoselectively.The E and Z configurations resulting unambiguously from these synthetic transformations were corroborated by the vicinal coupling constants of the cyclopropane ring protons.Ultraviolet spectroscopy confirmed the conjugative ability of the cyclopropane ring.