1,3-Dipolar Cycloadditions of Aldehydes or Imines with Carbonyl Ylides Generated from Epoxides:Classical Heating and Microwave Irradiation

摘要

Cycloadditions of aldehydes with carbonyl ylides to give dioxolanes have been carried out without solvent under microwave irradiation.The reactions proceeded in similar yields and stereoselectivities,but in shorter reaction times,than those obtained in toluene at reflux using an oil bath.Cycloadditions conducted between imines and carbonyl ylides using the same protocol were less efficient because the oxazolidines formed proved unstable under the reaction conditions.