1.Metallation of diacetals of 5-substituted-2-alkylthio-3-thiophenecarboxaldehydes with butyllithium in ether proceeds at the freeβ-position of the thiophene ring, so that different polyfunctional derivatives of thiophene can be synthesized.2.By the action of sodium in liquid ammonia on 5-methoxy-2-methylthio-3-thiophenecarboxaldehyde diethylacetal, and subsequent treatment with water, 5-methylthieno [3,2-d]isothiazole is formed.3.Certain intracoordination compounds of Co(II), Ni(II), and Zn were obtained which include the thiophene ring substituted in the α-position with a methoxy grou