Synthesis of 2‐acyl‐3‐methylthiofurans from 3‐methylthio‐2‐pentene‐1,5‐dione enolates

Abstract 2‐Acyl‐3‐methylthiofurans 3 are obtained in fair yields from 3‐methylthio‐2‐pentene‐1,5‐dione enolates 1 by reaction with iodine. In a similar reaction 1‐phenyl‐3‐methylthio‐4‐nitro‐2‐buten‐1‐one gave 3‐methylthio‐2‐nitro‐5‐phenylfuran 11. In the crystalline state the 2‐benzoyl‐3‐methylthio‐5‐phenylfuran 3b showed a non‐bonded sulfur‐oxygen interaction as inferred from an X‐ray diffraction determination, with a S····O distance of 2.871(5)Å.