2000 organo-phosphorus compounds, nonmetal heterocycles

organo-phosphorus compounds, nonmetal heterocyclesS 0087

16 - 171Organophosphorus Compounds. Part 144. A Novel Approach to1,3-Oxaphospholes from Phosphaalkynes and Isomuenchnones. —A novel facile and regioselective access to 1,3-oxaphosphole derivatives is pre-sented. Cycloaddition of isomuenchnones (VI), obtained by rhodium-catalyzedcyclization of diazooxopropanoates (III), to phosphaalkynes (IV) regiospecifi-cally provides bicyclic intermediates, which cannot be isolated and immediatelydecompose via a retro Diels–Alder reaction to provide oxophospholes (VII).This reaction sequence can also be carried out in one step without the isolationof isomuenchnones [cf. (III)→(V)]. — (RUF, SVEN G.; BERGSTRAESSER,UWE; REGITZ, MANFRED; Tetrahedron 56 (2000) 1, 63-70; FachbereichChem., Univ. Kaiserslautern, D-67663 Kaiserslautern, Germany; EN)

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