Synthesis of (±)-Methyl Epijasmonate and (±)-Methyl Dihydroepijasmonate by Diastereoselective Protonation
作者:Norbert Krause、Sophia Ebert
DOI:10.1002/1099-0690(200110)2001:20<3837::aid-ejoc3837>3.0.co;2-3
日期:2001.10
trans-isomer takes place to some extent, so that 1 was isolated with a cis:trans ratio of 72:28. The analogous transformation of enone 7 with lithium diallylcuprate and 2-(methyliminomethyl)phenol (4) furnished ketone 8 with 94% ds; this was then transformed into (±)-methyl dihydroepijasmonate (2) with a cis:trans ratio of 91:9. The olfactory properties of this product are superior to those available from commercial
(±)-甲基表茉莉酮酸酯 (1) 的合成通过二烯丙基铜酸锂与烯酮 3 的迈克尔加成和螯合质子源 2-(甲基亚氨基甲基)苯酚 (4; 85% ds) 的非对映选择性烯醇化物质子化,然后进行臭氧分解、氧化、酯化和 Lindlar 氢化。在臭氧化过程中,在一定程度上发生了向热力学更稳定的反式异构体的差向异构化,因此以 72:28 的顺式:反式比例分离了 1。烯酮 7 与二烯丙基铜酸锂和 2-(甲基亚氨基甲基)苯酚 (4) 的类似转化得到 94% ds 的酮 8;然后以 91:9 的顺式:反式将其转化为 (±)-二氢表茉莉酮酸甲酯 (2)。该产品的嗅觉特性优于商业来源的嗅觉特性