Abstract Thiophene and its derivatives with R= H, alkyl or− SCH 3 group in the 2-and 5- positions (1 and 4) undergo the following types of reaction with strong bases, depending upon the nature of the base and the solvent or solvent mixture: if R= H or alkyl: abstraction of the 2-and 5-proton in relatively apolar media and ring opening to enynethiolates in strongly polar media (HMPT); if R= CH 3 S: substitution on S in the SCH 3 group by butyllithium in ...
