Microwave heating enhanced the rate of three reactions typically performed in our undergraduate organic chemistry laboratory: a Diels-Alder cycloaddition, a Wittig salt formation, and a Williamson ether synthesis. Ninety-minute refluxes were shortened to 10 min using a laboratory-grade microwave oven. In addition, yields improved for the Wittig salt and ether preparations. The Diels-Alder cycloaddition of "N"-phenylmaleimide and 1,3-cyclohexadiene in absolute ethanol in a closed vessel and 130 [degree]C gave 84-90% yields. Formation of the Wittig salt, benzyltriphenylphosphonium chloride, from triphenylphosphine and benzyl chloride gave yields greater than 90% when heated in acetonitrile at 200 [degree]C Yields doubled in the Williamson ether synthesis of 2-ethoxynaphthalene, from 2-naphthol, methanolic potassium hydroxide, and iodoethane with microwave heating at 130 [degree]C. (Contains 1 table and 7 notes.)