Chiral methyl trans-2,2-dichloro-3-methylcyclopropanecarboxylate upon exposure to thiophenolate nucleophile
作者:Vitaly N. Kovalenko
DOI:10.3998/ark.5550190.p008.380
日期:——
Substitution of the β-halogen atoms in methyl (1R,3S)-2,2-dichloro-3-methylycyclopropanecarboxylate with sodium thiophenolate leads to the di(phenylthio) ester (1RS,3S)-4 as a mixture of diastereomers. The cis-trans isomerisation of methyl (1RS,3S)-3-methyl-2,2-bis(phenylthio)cyclopropanecarboxylate 4, basic hydrolysis and subsequent crystallization gave the corresponding acid (1R,3S)-5 in high diastereomeric
(1R,3S)-2,2-二氯-3-甲基环丙烷羧酸甲酯中的 β-卤素原子被苯硫酚钠取代,得到二(苯硫基)酯 (1RS,3S)-4,为非对映异构体的混合物。(1RS,3S)-3-甲基-2,2-双(苯硫基)环丙烷羧酸甲酯 4 的顺反异构化、碱性水解和随后的结晶得到相应的酸 (1R,3S)-5,具有高非对映体和对映体纯度. 另一方面,酯 (1RS,3S)-4 在酸性条件下开环生成 3-甲基-4,4二(苯硫基)丙-3-烯酸甲酯 (8) 或手性 S-苯基硫酯甲酯 ( 3S)-3-methyl-4-oxo-4(phenylthio)butanoate (7)。