Propellanes. XLVI. Steric and electronic effects as observed in reactions of propellanes
Pure and Applied Chemistry
The use of different propellane substrates indicates for a number of chemical reactions that either repulsive steric interactions of the reactants or attractive interactions of the secondary orbital type control the configuration of the product. The structure of propellanes is such that the three constituent rings divide space into three distinct sectors. It is therefore possible to use suitably constructed propellanes in the study of stereospecific and regiospecific reactions. Thus, if we have
... a propellane comprising three different rings as indicated by the descriptors a, b, c in its Newman projection A we may observe attack of ring a by a reagent operating within the sector defined by rings a änd b or within the sector defined by rings a and c, and analogously we may observe attack of ring b or ring c in the alternatively possible sectors. Wehave reported on the employment of propellanes as stereochemical models in simpler cases, i.e. in compounds of type! having c2v symmetry (1,2).