(2R,3R)-(+)- and (2S,3S)-(-)-2,3-epoxy-2-methylbutanoic acids (epoxyangelic acids) were prepared from (Z)-2-methyl-2-butenoic acid using the Sharpless asymmetric epoxidation method in combination with the use of(-)and (+)-menthol as chiral auxiliaries. Both substances, obtained in high enantiomeric excess, were characterized by spectroscopic and optical activity data. Their absolute configuration was determined by correlation with (R)-(+)-2-methyl-1,2-butanediol. (C) 1998 Elsevier Science Ltd. All rights reserved.
(2R,3R)-(+)- 和 (2S,3S)-(-)-2,3-环氧-
2-甲基丁酸((epoxyangelic acids) 由 (Z)-
2-甲基-2-丁烯酸通过结合使用 (-) 和
(+)-薄荷醇作为手性辅剂的Sharpless不对称环氧化法制得。两种物质均以高光学纯度获得,通过光谱和旋光性数据进行了表征。它们的绝对构型通过与 (R)-(+)-
2-甲基-1,2-丁二醇相关联来确定。© 1998 Elsevier Science Ltd. 保留所有权利。