Preparation and X-ray crystal-structure determinations of structural isomers of ferrocenyl-substituted dihydrofurans

Abstract

The reaction of tris(3-iodopentane-2,4-dionato)cobalt(III) with vinylferrocene in the presence of triphenylphosphine and a catalytic amount of Pd^II produced two structural isomers. The characterisation of these isomers, 2- and 3-ferrocenyl-4-acetyl-2,3-dihydro-5-methylfuran [(B) and (C), respectively] is described. Their structures have been determined by single-crystal X-ray diffractometry: (B) is orthorhombic, space group Pbca with a= 9.821 (2), b= 10.414(4), c= 27.761(6)Å, final R= 0.031, R′= 0.050 for 1 706 reflections; (C) is monoclinic, space group P2₁/_c with a= 9.692(1), b= 7.678(5), c= 19.082(3)Å, β= 97.76(1)°, final R= 0.031, R′= 0.048 for 1 641 reflections.