Reductive Amination of Pentacyclo(5.4.0.0(2,6).0(3,10).0(5,9))undecane-8,11-dione

摘要

Sodium cyanoborohydride is a highly selective reducing agent which is stable to pH 3 in aqueous acidic solution. Its ability to preferentially reduce iminium ions in the presence of ketone or aldehyde carbonyl groups renders it suitable for use as a reagent in the reductive amination of aldehydes and ketones. As part of an ongoing program that is concerned with the synthesis and chemistry of new, substituted pentacyclo(5.4.0.02,6.03,10.05,9) undecanes, we have investigated the reductive amination of the title compound by using sodium cyanoborohydride in the presence of ammonium bromide. In our hands, the reaction with sodium cyanoborohydride in the presence of ammonium bromide at pH 7.5-8.0 afforded a mixture of three products. One product, could be isolated in pure form via careful fractional crystallization of the product mixture (see Experimental Section). However, the remaining mixture of cage diamine and cage diol proved to be intractable. Reprints. (mjm)