DIASTEREO-DIFFERENTIATING CYCLOPROPANATION OF A CHIRAL ENOL ETHER: A SIMPLE METHOD FOR THE PREPARATION OF OPTICALLY PURE CYCLOPROPYL ETHERS

Article abstract of DOI:10.1016/S0040-4020(01)87920-5

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 95.2percent in the case of PD and over 99.5percent in the case of DMHD.The enol ethers prepared from various ketones and DMHD were also cyclopropanated in giving cyclopropyl ethers in almost 100percent d.e..