2-(ortho-Hydroxyphenyl)-alkynethiolates and-selenolates, obtained through base catalyzed ring cleavage of 4-(ortho-hydroxyphenyl)-1, 2, 3-thiadiazoles and-1, 2, 3-selenadiazoles, smoothly transform into 2-benzofuranthiolates and-selenolates. These reactive intermediates can be alkylated in high yield. This reaction sequence could be applied to the synthesis of electron rich thiacrown ethers. The 2-(ortho-aminophenyl)-alkynethiolate ...