Diastereo-differentiating cyclopropanation of a chiral enol ether: a simple method for the preparation of optically pure cyclopropyl ethers
作者:Takashi Sugimura、Masato Yoshikawa、Tohru Futagawa、Akira Tai
DOI:10.1016/s0040-4020(01)87920-5
日期:1990.1
Enol ether of cyclohexanone carrying 2,4-pentanediol(PD) or 2,6- dimethyl-3,5-heptanediol(DMHD) as a chiral auxiliary was subjected to diastereo-differentiating cyclopropanation. The highest diastereomer excess(d.e.) of the product was found to be 95.2% in the case of PD and over 99.5% in the case of DMHD. The enol ethers prepared from various ketones and DMHD were also cyclopropanated in giving cyclopropyl
将带有2,4-戊二醇(PD)或2,6-二甲基-3,5-庚二醇(DMHD)作为手性助剂的环己酮的烯醇醚进行非对映异构化环丙烷化。发现对于PD而言,产物的最高非对映异构体过量(de)为95.2%,对于DMHD而言,为超过99.5%。还对由各种酮和DMHD制备的烯醇醚进行了环丙烷化反应,制得了几乎100%de的环丙基醚。