Diastereoselective cyclopropanation of cyclic enones with methyl dichloroacetate anion
摘要:
The reaction of alpha,beta -unsaturated cyclic ketones with methyl dichloroacetate anion in the presence of DBU leads to the corresponding bicyclic chlorocyclopropanes in a highly diastereoselective fashion. In the cases of 2-cyclopentenone and 2-cyclohexenone the reaction affords exclusively the endo-Cl isomer. (C) 2001 Elsevier Science Ltd. All rights reserved.