Generation and Thermal Reactions of 2-Methyl-4-oxo-2-selenoniochroman-3-ide

Article abstract of DOI:10.1021/jo00384a002

The thermal reaction of 2-methyl-4-oxo-2-selenoniochroman-3-ide (4) in aprotic solvents afforded (E)-bis<2-<(methylseleno)methyl>benzoyl>ethylene (5) and trans-1,2,3-tris<2-<(methylseleno)methyl>benzoyl>cyclopropane (6) via a carbene intermediate.Ethanol reacted thermally with 4 to open the chroman ring, giving ethyl 2-<(methylseleno)methyl>benzoate (9a) and ethyl 2-(ethoxymethyl)benzoate (10a), whereas reaction with methanol yielded only methyl 2-<(methylseleno)methyl>benzoate (9b).Hydrolysis of ylide 4 eliminated dimethyl selenide, giving phthalide and 2-(hydroxymethyl)benzoic acid.