Large scale synthesis of N-protected 2,3-methanomethionine stereoisomers

Article abstract of DOI:10.1055/s-1996-4425

Three stereoisomers of N-protected forms of 2,3-methanomethionine (cyclopropyl derivatives of methionine, or 'cyclo-Met') were prepared. Two of the syntheses developed involved diol (S)-1, which was more easily obtained from L-gulono-1,4-lactone than via juxtaposition of the benzyl protection of (R)-1. The cis-cyclo-Met derivative (cis refers to the orientation of the side chain relative to the amino functionality), FMOC-(2R,3S)-cyclo-Met, was obtained via a route based on a previous synthesis of (2R,3S)-cyclo-Met from the lactone 3, but the protected trans-cyclo-Met, BOC-(2S,3S)-cyclo-Met, was obtained via an improved procedure that does not involve lactone 3.