Condensation of 2,3‐Di(methylidene)‐7‐oxabicyclo[2.2.1]heptane Derivatives into Dicarbonyl[η³:η³‐octa‐2,6‐diene‐1,8‐diyl]iron Complexes with Nonacarbonyldiiron. Crystal Structure of (1RS,2RS,3RS,4SR,5RS,6SR,1′RS,2′RS,3′RS,4′SR,5′RS,6′SR)‐Dicarbonyl‐{(2,3,C‐η:2′,3′,C‐η)‐2,2′‐ethylene‐5,5′,6,6′‐tetrakis[(methanesulfonyloxy)‐methyl]‐3,3′‐di(methylidene)‐bis[7‐oxabicyclo[2.2.1]hept‐2‐yl]}iron

Abstract

The reactions of [Fe2(CO)9] with 2‐exo,3‐exo‐bis(chloromethyl)‐5,6‐di(methylidene)‐7‐oxabicycio[2.2.1]‐heptane (5) and with 5,6‐di(methylidene)‐7‐oxabicyclo[2.2.1]heptane‐2‐exo,3‐exo‐dimethyl bis(methanesulfonate) (6) afforded, together with the corresponding [exo‐Fe(CO)3(1,3‐diene)] complexes 7 and 8, the products of dimerization in the form of stable [Fe(CO)2{(1,2,3‐η:6,7,8‐η)‐octa‐2,6‐diene‐1,8‐diyl}] complexes 9 and 10, respectively, with high stereoselectivity. The structure of 10 was established by means of single‐crystal X‐ray diffraction.