COC1=C(C(=O)OC(C)(C)C)[C@]2(C)C(C(=O)OC(C)(C)C)C(OC)=C(C(=O)OC(C)(C)C)[C@]2(C)C1C(=O)OC(C)(C)C
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. How many bonds in the molecule are rotatable?