Synthesis of conformationally rigid sugar-fused lactones and sugar α-amino acids

Abstract

The synthesis of conformationally constrained non-anomeric furanoid sugar quaternary α-amino acids and sugar-fused δ- and γ-lactones from d-glucose have been accomplished. The furanoid sugar α-amino acids were accessed via generation of the quaternary centre at the C-3 position of glucose with the installation of amine and nitrile functionality producing the aminonitrile derivative as a single diastereomer. The Pinner cyclisation of the C-6 primary hydroxy of amino nitrile derivative paved the way for the formation of the glucose-fused δ-lactone. The basic hydrolysis of these sugar lactones and other subsequent reactions produced sugar-fused γ-lactone and sugar-templated aspartic acid, keto-functionalized glutamic acid, and homoserine.