Parallel synthesis of individual shikimic acid-like molecules using a mixture-operation strategy and ring-closing enyne metathesis

Three new diastereomeric shikimic acid analogues (4-amino-3,5-dihydroxyl-cyclohex-1-en-carboxylic acids, 16) bearing a C-4 amino group were synthesized in parallel by a mixture-operation protocol. Ring-closing enyne metathesis (RCEYM) under ethylene atmosphere was successfully employed to construct the desired carbocycles in high efficiency. The absolute configurations of each final product were confirmed by the 1D and 2D NMR techniques.