Abstract Four synthetic routes to poly (L-lactide) with thiol end groups based on ring-opening polymerization of L-lactide (LA) catalysed with tin (II) 2-ethylhexanoate (Sn (Oct) 2) are reported. The following alcohols were used as co-initiators of polymerization: 2- sulfanylethan-1-ol, 2-[(2, 4-dinitrophenyl) sulfanyl] ethan-1-ol, 2-(tritylsulfanyl) ethan-1-ol and allyl alcohol. End groups introduced into polymers by co-initiators were transformed to ...