Regioselective Tritiation of Carbamate Dicyclic Juvenoids

Abstract

The tritiated juvenoids ethyl N-{2-[4-(cis-2-hydroxy-1-cycloheptylmethyl)phenoxy]ethyl}carbamate (1), 2-[4-(trans-2-hydroxy-1-cyclohexylmethyl)phenoxy]ethyl N-ethylcarbamate (2) and ethyl N-{2-[4-(c-2-hydroxy-3-methyl-r-1-cyclohexylmethyl)phenoxy]ethyl}carbamate (3) were prepared by Catalyzed Exchange in Solution with Gas on PdO/BaSO4. The high degree of regio- and stereoselectivity observed in the products by 3H NMR is discussed in the terms of the stereoelectronic requirements of the exchange reaction.