Tetrahedron letters

Intramolecular carbenoid insertions into thiophene: Reactions of 1-diazo-3-(2-thienyl)-2-propanone and 1-diazo-3-(3-thienyl)-2-propanone

CS Frampton, DL Pole, K Yong, A Capretta

Index: Frampton, Christopher S.; Pole, David L.; Yong, Kelvin; Capretta, Alfredo Tetrahedron Letters, 1997 , vol. 38, # 29 p. 5081 - 5084

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Citation Number: 11

Abstract

Treatment of 1-diazo-3-(2-thienyl)-2-propanone with catalytic rhodium (II) acetate results in cyclopropanation followed by acid-catalyzed ring opening and tautomerization to yield 5, 6- dihydro-4H-cyclopenta [b] thiopen-5-one. Under the same conditions, however, the isomeric 1-diazo-3-(3-thienyl)-2-propanone generates a cyclopropane intermediate which undergoes [4+ 2] cycloreversion, isomerization and Diels-Alder dimerization to give a complex spiro- ...