Reactions were performed in nitrogen-purged Me2S0 in the presence of equimolar amounts of 18-crown-6, with irradiation from a 275-W sunlamp positioned ca. 15 cm from the Pyrex reaction flask.* Generated by the action of potassium tert-butoxide on the conjugate acid.'Yields determined by IH NMR and GLC on a I-mmol scale for reactions 0.1 M in RHgX N N-. dBased upon a series of experiments in Me2S0 at different N-and Me2C= N02- ...