methanol to give α-azido methyl esters in good overall yields. Catalytic hydrogenation of the α-azido esters afforded α-quaternary α-amino acid methyl esters in quantitative yields. Starting from β-tetralone and optically pure (R)-chloromethyl p-tolyl sulfoxide, an asymmetric synthesis of optically pure (R)-(+)-methyl 2-aminotetraline-2-carboxylate was realized in good overall yields.
亚砜基
肟基酮是由酮和
氯甲基
对甲苯基亚砜分两步合成的,几乎可以定量收率。在NH 4 Cl的存在下,用NaN 3处理亚砜基
肟基,得到α-
叠氮基醛,然后在
甲醇中,在KOH的存在下,用
碘将其氧化,得到α-
叠氮基甲基酯,总收率良好。α-
叠氮基酯的催化氢化以定量收率得到α-季
铵α-氨基酸甲基酯。从
β-四氢萘酮和旋光纯的(R)-
氯甲基
对甲苯基亚砜开始,以良好的总收率实现了旋光纯的(R)-(+)-甲基2-
氨基四环-2-
羧酸酯的不对称合成。