1
COC1=C2C3=C(C(=O)CC3)C(=O)OC2=C4C5C=COC5OC4=C1
2
COC1=C2C3=C(C(=O)OCC3)C(=O)OC2=C4C5C=COC5OC4=C1
3
COC1=C2C3=C(C(=O)CC3)C(=O)OC2=C4C5CC(OC5OC4=C1)O
4
COC1=C2C3=C(C(=O)CC3)C(=O)OC2=C4C(=C1)OC5C4(C=CO5)O