The Conservation of Orbital Symmetry

The principle of orbital symmetry conservation was first proposed by Woodward and Hoffmann in 1965 to explain the stereochemistry of electrocyclic reactions. The Conservation of Orbital Symmetry was published in 1969 as an article in Angewandte Chemie International Edition in English. Due to its popularity, it was subsequently republished as a booklet by Academic Press and Verlag Chemie in 1970. Woodward and Hoffmann famously stated the generalized pericyclic selection rules in this publication, which would come to be known as the Woodward-Hoffmann rules. The conservation of orbital symmetry would become the basis of Hoffmann's Nobel Prize in Chemistry (1981, shared with Kenichi Fukui; Woodward died in 1979). Elsevier reissued the Jan. 1971 third printing of the booklet in 2014. This is an electronic copy (without DRM) in pdf form (1200 dpi color, conforms to PDFA, and contains optical character recognition). --ymw