Intermolecular photoreaction of thiohomophthalimides with olefins: Thietane formation through [2 + 2] cycloaddition

Article abstract of DOI:10.1055/s-1992-26225

Upon irradiation of thiohomophthalimides (1,2,3,4-tetrahydro-2,4,4-trimethyl-1,3-dithioxo[3-oxo-1-thioxo or 1-oxo-3-thioxo]isoquinolines, 1-3) in the presence of olefins 4, 9, regioselective [2 + 2] cycloaddition occurred to give oxo- or thioxospiro[isoquinoline-1,2'(or 3,2')-thietane] derivatives 5, 6, 8, 10-12 and related compounds 1-alkylidene-1,2,3,4-tetrahydro-2,4,4-trimethyl-3-thioxoisoquinolines 7a, c.