BrC(=C1SC(C(=O)OC)=C(S1)C(=O)OC)C(=C2SC(C(=O)OC)=C(S2)C(=O)OC)C(C(Br)=C3SC(C(=O)OC)=C(S3)C(=O)OC)=C4SC(C(=O)OC)=C(S4)C(=O)OC