In Gegenwart von Phosphorsäure kondensieren die Chromanone und Thiochromanone (I) mit den Benzaldehyden (II) zu den Benzylidenchromanonen (III), die thermisch in Gegenwart einer sehr geringen Menge Piperidin zu den Benzylchromonen (IV) isomerisieren.

Enantioselective syntheses Enantioselective syntheses O 0031Electronic and Steric Effects of Ligands as Control Elements for Rhodium-Catalyzed Asymmetric Hydrogenation. -Investigation of the influence of the arene substituent on (S)-H8-BINOL diphosphinite catalyst ligand provides improved enantioselectivity for the Rh-catalyzed hydrogenation of diethyl itaconate (I) and (Z)-α-acetamido cinnamate (III). -(GERGELY, I.; HEGEDUES, C.; SZOELLOESY, A.; MONSEES, A.; RIERMEIER, T.; BAKOS*, J.; Tetrahedron Lett. 44 (2003) 50, 9025-9028; Dep. Org. Chem., Univ. Veszprem, H-8201 Veszprem, Hung.; Eng.) -Mais 13-032

Organo-phosphorus compoundsOrgano-phosphorus compounds S 0080 Unexpected Condensation Reaction of Two Units of 1,2-Dihydrophosphinine 1-Oxides in the Presence of Tetracyanoethylene. -The reaction of the title dihydrophosphinine oxides (I) with tetracyanoethylene in refluxing benzene affords unexpectedly diphosphatricyclododecatrienes (III) instead of the corresponding Diels-Alder cycloadducts. Structures of compounds (III) are elucidated by spectroscopic methods and quantum chemical calculations. -(KEGLEVICH*, G.; KOVACS, J.; SZOELLOESY, A.; KOVACS, A.; SZABO, A.; LUDANYI, K.; KADAS, I.; TOEKE, L.; Heteroat. Chem. 14 (2003) 1, 29-35; Dep. Org. Chem. Technol., Budapest Univ. Technol. Econ., H-1521 Budapest, Hung.; Eng.) -M. Schroeter 21-156

Synthesis of Isoplagiochin A.-A convergent synthesis of title compound (IX), a plant metabolite isolated from plagiochila fruticosa, is presented. -(GERENCSER, J.; KESERUE, G. M.; MACSARI, I.; NOGRADI, M.; KAJTAR-PEREDY, M.; SZOELLOESY, A.; J.

Treatment of the 3‐phosphabicyclo(3.1.0)hexane 3‐oxides (Ia) and (Ib) with mercury acetate (II) in acetic acid causes cleavage of the cyclopropane ring, forming the diastereo‐ and regioisomeric phosphorin 1‐oxides (III) and (IV).