Chemistry of O-alkyl selenoesters. Reaction with triethylphosphine

Abstract

The reactions between triethylphosphine and a number of aliphatic and aromatic selenoesters under oxygen-free conditions have been investigated. The purple intermediate formed in the reaction with the aliphatic selenoesters was quenched with atmospheric oxygen and gave the corresponding esters, whereas quenching with methyl iodide gave the corresponding 1-alkoxy-1-iodoalkyltriethylphosphonium iodides (13)–(16). The 1-alkoxy-1-iodoalkyltriethyiphosphonium iodides gave the 1-alkoxyalkyltriethylphosphonium iodides (17)–(20) upon treatment with methanol, and treatment with benzaldehyde at –70 °C gave α-alkoxyalkyl phenyl ketones (22)–(25). The reaction between the selenobenzoates and triethylphosphine gave α-dialkoxy-stilbenes and -dibenzyls. When the reaction was carried out in cyclohexene 7-alkoxy-7-phenylbicyclo[4.1.0]heptanes were formed. The presence of benzaldehyde in the reaction mixture led to α-alkoxystilbenes. An explanation for these different reactions is presented.