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-(2R,3S)-cyclo-Met, was obtained via an improved procedure that does not involve lactone 3.
我们制备了三种 2,3-甲
硫氨酸 N 保护形式的立体异构体(甲
硫氨酸的环丙基衍
生物,或称 "环甲
硫氨酸")。其中两种合成涉及二元醇 (S)-1,它更容易从 L-古洛
萘-1,4-内
酯中获得,而不是通过并置
苄基保护的 (R)-1。顺式环-Met 衍
生物(顺式指侧链相对于
氨基官能团的取向)F
MOC-(2R,3S)-环-Met 是通过以前从内
酯 3 合成 (2R,3S)-cyclo-Met 的路线获得的,但受保护的反式环-Met BOC-(2R,3S)-cyclo-Met 则是通过一种不涉及内
酯 3 的改进程序获得的。