<MultiModal>![CCS(CC1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O)=O>CC1=CC=C(S(=O)(O)=O)C=C1.CC(OC(C)=O)=O,$\mathrm{xylene}$,$\mathrm{reflux}$>[$\mathbf{A}$],$\mathbf{A}$ is the product](/media/uploads/d8a4a7bf-ee40-47cf-afbb-076563a6a10b.png)</MultiModal>

Given that the molecular formula of the reaction product $\mathbf{A}$ is $\mathrm{C_{15}H_{15}NO_3}$, and $\mathbf{A}$ contains three rings, provide the structural formula of $\mathbf{A}$.
<MultiModal>![CCS(CC1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O)=O>CC1=CC=C(S(=O)(O)=O)C=C1.CC(OC(C)=O)=O,$\mathrm{二甲苯}$,$\mathrm{回流}$>[$\mathbf{A}$],$\mathbf{A}$是产物](/media/uploads/d8a4a7bf-ee40-47cf-afbb-076563a6a10b.png)</MultiModal>

已知反应产物$\mathbf{A}$的分子式为$\mathrm{C_{15}H_{15}NO_3}$，$\mathbf{A}$中含有三个环，试给出$\mathbf{A}$的结构式
All other options are incorrect
<MultiModal>![CN(CC1)C2=C1C(C(O)=O)=C(OC)C3=CC=CC=C32](/media/uploads/96ff2602-b74b-4a84-941d-826e1f6c76d5.png)</MultiModal>
<MultiModal>![CN1C(C2=CC=CC=C2CO3)=C(C(OC)=O)C3C=C1](/media/uploads/88e2bdea-c06c-41f2-95c8-8710ad234ad0.png)</MultiModal>
<MultiModal>![CN1C(C2=CC=CC=C2C3=O)=C(C(OC)=O)C3CC1](/media/uploads/483ec6ff-8912-46a2-b47b-e1d098257f65.png)</MultiModal>
<MultiModal>![CN(C=CC1C2C(OC)=O)C2C3=CC=CC=C3C1=O](/media/uploads/756e205e-ddee-4d63-8ed2-e7dbac0a4abd.png)</MultiModal>
<MultiModal>![OC1=C(C(OC)=O)C2=C(N(C)CC2)C3=CC=CC=C31](/media/uploads/b5bb74ba-dae9-47b5-b83b-838b640f9828.png)</MultiModal>
其他选项均不正确
<MultiModal>![CN(CC1)C2=C1C(C(O)=O)=C(OC)C3=CC=CC=C32](/media/uploads/96ff2602-b74b-4a84-941d-826e1f6c76d5.png)</MultiModal>
<MultiModal>![CN1C(C2=CC=CC=C2CO3)=C(C(OC)=O)C3C=C1](/media/uploads/88e2bdea-c06c-41f2-95c8-8710ad234ad0.png)</MultiModal>
<MultiModal>![CN1C(C2=CC=CC=C2C3=O)=C(C(OC)=O)C3CC1](/media/uploads/483ec6ff-8912-46a2-b47b-e1d098257f65.png)</MultiModal>
<MultiModal>![CN(C=CC1C2C(OC)=O)C2C3=CC=CC=C3C1=O](/media/uploads/756e205e-ddee-4d63-8ed2-e7dbac0a4abd.png)</MultiModal>
<MultiModal>![OC1=C(C(OC)=O)C2=C(N(C)CC2)C3=CC=CC=C31](/media/uploads/b5bb74ba-dae9-47b5-b83b-838b640f9828.png)</MultiModal>
First, the oxygen atom in the sulfoxide is acetylated to obtain intermediate $\mathbf{1}$

<MultiModal>![Intermediate $\mathbf{1}$:CC[S+](OC(C)=O)CC1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](/media/uploads/4a4bb170-450e-4b1d-9549-bab3ae00597a.png)</MultiModal>

<Checkpoint>[Intermediate $\mathbf{1}$:CC[S+](OC(C)=O)CC1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](1)</Checkpoint>

Next, elimination of one molecule of acetic acid yields the reaction intermediate $\mathbf{2}$

<MultiModal>![Intermediate $\mathbf{2}$:CC/[S+]=C/C1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](/media/uploads/71fdb928-76bf-48b1-9160-a89071b9e03c.png)</MultiModal>

<Checkpoint>[Intermediate $\mathbf{2}$:CC/[S+]=C/C1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](1)</Checkpoint>

The adjacent oxygen atom nucleophilically attacks the carbocation to form a five-membered ring, yielding intermediate $\mathbf{3}$

<MultiModal>![Intermediate $\mathbf{3}$:CCSC1C2=CC=CC=C2C(N(CC/C=C/C(OC)=O)C)=[O+]1](/media/uploads/3b83a597-b3e4-458f-8ab6-3de64b113b93.png)</MultiModal>

<Checkpoint>[Intermediate $\mathbf{3}$:CCSC1C2=CC=CC=C2C(N(CC/C=C/C(OC)=O)C)=[O+]1](1)</Checkpoint>

Next, deprotonation and aromatization yields intermediate $\mathbf{4}$

<MultiModal>![Intermediate $\mathbf{4}$:CCSC1=C2C(C=CC=C2)=C(O1)N(CC/C=C/C(OC)=O)C](/media/uploads/b9ca9088-a165-4f72-96f4-6f580b8d3e1a.png)</MultiModal>

<Checkpoint>[Intermediate $\mathbf{4}$:CCSC1=C2C(C=CC=C2)=C(O1)N(CC/C=C/C(OC)=O)C](1)</Checkpoint>

Next, an intramolecular DA reaction occurs to give intermediate $\mathbf{5}$

<MultiModal>![Intermediate $\mathbf{5}$:CCSC12C3=C(C4(O1)N(CCC4C2C(OC)=O)C)C=CC=C3](/media/uploads/a419158e-c6a6-43ba-9b5b-49c29abea925.png)</MultiModal>

<Checkpoint>[Intermediate $\mathbf{5}$:CCSC12C3=C(C4(O1)N(CCC4C2C(OC)=O)C)C=CC=C3](1)</Checkpoint>

Then, elimination of one molecule of thiolate anion yields intermediate $\mathbf{6}$

<MultiModal>![Intermediate $\mathbf{6}$:O=C1C2=C(C3=[N+](CCC3C1C(OC)=O)C)C=CC=C2](/media/uploads/67c381f1-4cb0-4c6a-b535-68f4d6a6df70.png)</MultiModal>

<Checkpoint>[Intermediate $\mathbf{6}$:O=C1C2=C(C3=[N+](CCC3C1C(OC)=O)C)C=CC=C2](1)</Checkpoint>

Finally, intermediate $\mathbf{6}$ undergoes aromatization to yield product $\mathbf{A}$

<MultiModal>![OC1=C(C(OC)=O)C2=C(N(CC2)C)C3=C1C=CC=C3](/media/uploads/af3767d9-0d9d-440e-8af8-164246ef5940.png)</MultiModal>
首先，亚砜中的氧原子被乙酰化，得到中间体$\mathbf{1}$

<MultiModal>![中间体$\mathbf{1}$
：CC[S+](OC(C)=O)CC1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](/media/uploads/4a4bb170-450e-4b1d-9549-bab3ae00597a.png)</MultiModal>

<Checkpoint>[中间体$\mathbf{1}$ ：CC[S+](OC(C)=O)CC1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](1)</Checkpoint>

接着，消除一分子乙酸得到反应中间体$\mathbf{2}$

<MultiModal>![中间体$\mathbf{2}$：CC/[S+]=C/C1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](/media/uploads/71fdb928-76bf-48b1-9160-a89071b9e03c.png)</MultiModal>

<Checkpoint>[中间体$\mathbf{2}$：CC/[S+]=C/C1=CC=CC=C1C(N(CC/C=C/C(OC)=O)C)=O](1)</Checkpoint>

临近的氧原子亲核进攻碳正离子形成五元环，得到中间体$\mathbf{3}$

<MultiModal>![中间体$\mathbf{3}$：CCSC1C2=CC=CC=C2C(N(CC/C=C/C(OC)=O)C)=[O+]1](/media/uploads/3b83a597-b3e4-458f-8ab6-3de64b113b93.png)</MultiModal>

<Checkpoint>[中间体$\mathbf{3}$：CCSC1C2=CC=CC=C2C(N(CC/C=C/C(OC)=O)C)=[O+]1](1)</Checkpoint>

接着去质子芳构化得到中间体$\mathbf{4}$

<MultiModal>![中间体$\mathbf{4}$：CCSC1=C2C(C=CC=C2)=C(O1)N(CC/C=C/C(OC)=O)C](/media/uploads/b9ca9088-a165-4f72-96f4-6f580b8d3e1a.png)</MultiModal>

<Checkpoint>[中间体$\mathbf{4}$：CCSC1=C2C(C=CC=C2)=C(O1)N(CC/C=C/C(OC)=O)C](1)</Checkpoint>

接着发生分子内DA反应，得到中间体$\mathbf{5}$

<MultiModal>![中间体$\mathbf{5}$：CCSC12C3=C(C4(O1)N(CCC4C2C(OC)=O)C)C=CC=C3](/media/uploads/a419158e-c6a6-43ba-9b5b-49c29abea925.png)</MultiModal>

<Checkpoint>[中间体$\mathbf{5}$：CCSC12C3=C(C4(O1)N(CCC4C2C(OC)=O)C)C=CC=C3](1)</Checkpoint>

然后脱去一分子硫醇阴离子得到中间体$\mathbf{6}$

<MultiModal>![中间体$\mathbf{6}$：O=C1C2=C(C3=[N+](CCC3C1C(OC)=O)C)C=CC=C2](/media/uploads/67c381f1-4cb0-4c6a-b535-68f4d6a6df70.png)</MultiModal>

<Checkpoint>[中间体$\mathbf{6}$：O=C1C2=C(C3=[N+](CCC3C1C(OC)=O)C)C=CC=C2](1)</Checkpoint>

最后中间体$\mathbf{6}$进行芳构化得到产物$\mathbf{A}$

<MultiModal>![OC1=C(C(OC)=O)C2=C(N(CC2)C)C3=C1C=CC=C3](/media/uploads/af3767d9-0d9d-440e-8af8-164246ef5940.png)</MultiModal>