Investigations on organolead compounds : II. The reaction of triphenylplumbyllithium with small-ring heterocycles: Functionally substituted organolead compounds

Abstract

The reactions between triphenylplumbyllithium and small-ring heterocycles have been studied. ▪ The reaction ran successfully with the following heterocycles: ethylene oxide, ethylene V83 V 2 sulphide, N-acylethylenimines and trimethylene oxide. No reaction occurred with ethylenimine, N-butylethylenimine, trimethylene sulphide and tetrahydrofuran. Some substituted rings also reacted in the expected way: epichlorohydrin gave a linear product, Ph 3PbCH 2CHOHCH 2Cl, and β-propiolactone gave primarily Ph 3PbCH 2CH 2COOH, which, however, spontaneously lost one molecule of benzene to give [Ph 2Pb -CH 2CH 2COO -] ▪; with diazomethane the acid could be trapped as the methyl ester. Ketene dimer and pyrrolidone caused decomposition of triphenylplumbyllithium. Treatment of the epichlorohydrin product, Ph 3PbCH 2CHOHCH 2Cl, with one equivalent of hydrogen chloride resulted in the elimination of the CH 2CHOHCH 2Cl group; whereas chlorination led merely to elimination of phenyl groups. This discrepancy is explained by assuming that protonation of the hydroxyl group (in case of treatment with hydrogen chloride) facilitates separation of the CH 2CHOHCH 2Cl group.