Abstract An asymmetric synthesis of (+)- and (–)-methiine (S-methyl-(R)-cysteine sulfoxide) diastereomers has been developed. These natural sulfur compounds were isolated from a variety of Brassica vegetables. As the starting compound, (R)-cysteine was used, which was methylated to form (R)-S-methylcysteine. Then the oxidation of S-methylcysteine with tert-butyl hydroperoxide catalyzed by the chiral tetra(isopropylate)titanium/(S)- or (R)-Binol complex led to the formation of (1 R,2S)-(+)- or (1 R,2R)-(–)-methiin stereomers. Graphical Abstract

中文翻译：

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(S,R)- 和 (R,R)-甲硫氨酸立体异构体的不对称合成

摘要 已经开发了 (+)- 和 (-)- 甲硫氨酸（S-甲基-（R）-半胱氨酸亚砜）非对映异构体的不对称合成。这些天然硫化合物是从各种芸苔属蔬菜中分离出来的。使用(R)-半胱氨酸作为起始化合物，将其甲基化形成(R)-S-甲基半胱氨酸。然后在手性四（异丙酯）钛/（S）-或（R）-Binol络合物催化下用叔丁基氢过氧化物氧化S-甲基半胱氨酸导致形成（1 R，2S）-（+）-或(1 R,2R)-(–)-甲硫氨酸立体异构体。图形概要