Heterogeneously catalyzed diastereoselective synthesis of 2-nitro-1,3-di(pyridin-2-yl)propane-1,3-diols

Abstract

2-Nitro-1,3-di(pyridin-2-yl)propane-1,3-diols 4a, 4b are prepared via nitroaldol (Henry) reaction in two separate steps by straightforward procedures. The employment of two solids as catalysts, namely the hydrotalcite Syntal 696® and the ion exchange resin Amberlyst A21® allows a simple work-up and leads to the diastereoselective formation of the (R,R)- and (S,S)-isomers. The solid-state structures of 4a, 4b as well as of their precursor compounds 3a and 3b were determined. Reaction of 4a with zinc chloride yields a mononuclear zinc chloride complex. To circumvent retro-reactions, trialkylsilyl protective groups are deployed. © 2011 Verlag der Zeitschrift für Naturforschung.