Highly Regioselective Synthesis of C-4 (Ring A) Sinomenine Ether Derivatives

Abstract

Seven sinomenine derivatives on ring A were synthesised from sinomenine and benzyl alcohol or an aliphatic alcohol as reactants, and triphenylphosphine and diethyl azodicarboxylate as the dehydrating agent. The structure of target compounds were characterised by 1 H NMR, 13 C NMR, MS spectra and elemental analysis. The yield was 78–94% under the optimised reaction conditions involving THF as solvent and at room temperature. The method is simple and the reaction conditions are mild with excellent target product selectivity. It may be widely used to modify these polyfunctional natural products.