Synthesis of 1-amino-3-[2-(1,7-dicarba-closo-dodecaboran(12)-1-yl)ethyl]cyclobutane-carboxylic acid: A potential BNCT agent

The synthesis of an unnatural amino add, 1-amino-3-[2-(1,17-dicarba-closo-dodecaboran(12)-1-yl)ethyl]cyclobutanecarboxylic acid, was achieved. This new potential BNCT agent was prepared via the mono alkylation of m-carborane with 4-bromobutene to produce 4-m-carboranyl-1-butene, which was then subjected to a 2 + 2 cycloaddition using dichloroketene. The resultant boronated cyclobutanone was reductively dechlorinated prior to the formation of the corresponding hydantoin, which was hydrolized to the title compound in excellent yield.