Compound $\bf{P}$ first reacts with TFAA, followed by the action of $Zn$ to generate $\bf{Q}$. $\bf{Q}$ generates $\bf{R}$ with a ketal structure under the action of acetic anhydride. $\bf{R}$ obtains the final product $\bf{X}$ with a fused hexacyclic-tricyclic system under the action of triethylamine. It is known that a new five-membered ring is produced in both the reaction from $\bf{P}$ to $\bf{Q}$ and from $\bf{Q}$ to $\bf{R}$.

<MultiModal>![C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O)C(C([C@H]3C)=O)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C first reacts with trifluoroacetic anhydride and DMAP in DCM, followed by reaction with zinc, DMAP, and acetic acid to obtain $\bf{Q}$. $\bf{Q}$ reacts with acetic anhydride and DMAP in DCM to obtain $\bf{R}$. $\bf{R}$ and triethylamine react in DMF at 60 degrees Celsius to obtain $\bf{X}$: C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)4C)[C@]4(C([C@H]3C)=O)OC(C)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C](/media/uploads/bc5576d5-0bfa-4ca5-8717-220f8e6e2711.png)</MultiModal>

The following statements are made:

1.  The role of $Zn$ in the step of generating $\bf{Q}$ is as a reducing agent.

2.  There is a trans-vicinal diol structure in $\bf{Q}$.

3.  There is a carbon atom bonded to three oxygen atoms in $\bf{R}$.

4.  It is known that the process of generating $\bf{X}$ successively undergoes two negatively charged intermediates $\bf{Y1}$ and $\bf{Y2}$, then $\bf{Y2}$ has 3 rings.

Select the option containing all correct statements.
化合物$\bf{P}$首先与TFAA反应，紧接着在$Zn$的作用下生成$\bf{Q}$，$\bf{Q}$在乙酸酐的作用下生成具有缩酮结构的$\bf{R}$，$\bf{R}$在三乙胺的作用下得到具有六元环并三元环环系的最终产物$\bf{X}$。已知$\bf{P}$到$\bf{Q}$，$\bf{Q}$到$\bf{R}$均有一个新的五元环产生。

<MultiModal>![C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O)C(C([C@H]3C)=O)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C首先与三氟乙酸酐、DMAP在DCM中反应，随后与锌、DMAP和乙酸反应得到$\bf{Q}$，$\bf{Q}$在乙酸酐、DMAP在DCM中反应得到$\bf{R}$，$\bf{R}$和三乙胺在60摄氏度下在DMF中反应得到$\bf{X}$：C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)4C)[C@]4(C([C@H]3C)=O)OC(C)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C](/media/uploads/bc5576d5-0bfa-4ca5-8717-220f8e6e2711.png)</MultiModal>

有以下说法：

1.生成$\bf{Q}$一步$Zn$的作用是作为还原剂

2.$\bf{Q}$中存在反式邻二醇结构

3.$\bf{R}$中存在与三个氧原子成键的碳原子

4.已知生成$\bf{X}$的过程中先后经历了两个带负电荷的中间体$\bf{Y1}$和$\bf{Y2}$，则$\bf{Y2}$中有3个环

选出含有说法全部正确的一项
All statements are incorrect.
1
2
3
4
1,2
1,3
1,4
2,3
2,4
3,4
1,2,3
1,2,4
1,3,4
2,3,4
1,2,3,4
所有说法均不正确
1
2
3
4
1,2
1,3
1,4
2,3
2,4
3,4
1,2,3
1,2,4
1,3,4
2,3,4
1,2,3,4
TFAA is a strong acylation reagent. Under DMAP catalysis, the tertiary alcohol hydroxyl group in $\bf{P}$ is more nucleophilic than the oxygen of the enol ether or the enol oxygen of the 1,3-diketone, and will preferentially react with TFAA to generate a trifluoroacetate. Subsequently, zinc reduction of the vicinal diketone in acetic acid produces an enol, which attacks the trifluoroacetate to generate a five-membered ring.

<Checkpoint>[$Zn$ acts as a reducing agent to reduce the vicinal diketone, statement 1 is correct](1)</Checkpoint>

During the nucleophilic attack, zinc ion chelation controls the oxygen of the trifluoroacetate and the enol oxygen produced by the vicinal diketone to be on the same side, resulting in $\bf{Q}$: `C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)O)[C@]4(C([C@H]3C)=O)O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`. It has a *cis*-vicinal diol structure.

<Checkpoint>[The structure of $\bf{Q}$ is `C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)O)[C@]4(C([C@H]3C)=O)O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`. It has a *cis*-vicinal diol structure. Statement 2 is incorrect](1)</Checkpoint>

Under the action of acetic anhydride, the newly generated hydroxyl group of $\bf{Q}$ is converted to an acetate. Due to the vicinal diol structure, the other hydroxyl group can attack the ester group, generating a five-membered ring, resulting in $\bf{R}$: `C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H]4[C@]5(C([C@H]3C)=O)O[C@](O)(C)O[C@]5(C(F)(F)F)OC(C)4C)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`, in which there is a carbon atom bonded to three oxygen atoms.

<Checkpoint>[The structure of $\bf{R}$ is `C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H]4[C@]5(C([C@H]3C)=O)O[C@](O)(C)O[C@]5(C(F)(F)F)OC(C)4C)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`, in which there is a carbon atom bonded to three oxygen atoms. Statement 3 is correct](1)</Checkpoint>

Under the action of base, the hydroxyl hydrogen on the orthoester is abstracted, and the orthoester decomposes to generate intermediate $\bf{Y1}$: `C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)[O-])[C@]4(C([C@H]3C)=O)OC(C)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`. Subsequently, the negative charge on the oxygen attacks the carbon-carbon bond, and a retro-Aldol reaction occurs, opening the five-membered ring to generate enol $\bf{Y2}$: `C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)OC(C(F)(F)F)=O)C(OC(C)=O)=C([C@H]3C)[O-])[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`, which has 3 rings. The enolate anion attacks the carbon atom connected to the trifluoroacetate oxygen, generating a three-membered ring, and trifluoroacetate is eliminated, generating $\bf{X}$.

<Checkpoint>[The structure of $\bf{Y2}$ is `C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)OC(C(F)(F)F)=O)C(OC(C)=O)=C([C@H]3C)[O-])[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`, which has 3 rings. Statement 4 is correct](1)</Checkpoint>

Statements 1, 3, and 4 are correct, choose N.

<MultiModal>![$\bf{Q}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)O)[C@]4(C([C@H]3C)=O)O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`；$\bf{R}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H]4[C@]5(C([C@H]3C)=O)O[C@](O)(C)O[C@]5(C(F)(F)F)OC(C)4C)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`；$\bf{Y1}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)[O-])[C@]4(C([C@H]3C)=O)OC(C)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`；$\bf{Y2}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)OC(C(F)(F)F)=O)C(OC(C)=O)=C([C@H]3C)[O-])[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`](/media/uploads/fc166431-eabb-42d1-b265-b1fd4c765d65.png)</MultiModal>
TFAA是强酰化试剂。在DMAP催化下，$\bf{P}$中的叔醇羟基比烯醇醚的氧或1,3-二酮的烯醇氧更具亲核性，会优先与TFAA反应，生成三氟乙酸酯。随后在乙酸中的锌还原邻二酮产生烯醇，进攻三氟甲酸酯，产生五元环。

<Checkpoint>[$Zn$的作用是作为还原剂，还原邻二酮，说法1正确](1)</Checkpoint>

亲核进攻时，锌离子螯合控制三氟甲酸酯的氧与邻二酮产生的烯醇氧处于同侧，得到$\bf{Q}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)O)[C@]4(C([C@H]3C)=O)O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`。具有顺式邻二醇结构。

<Checkpoint>[$\bf{Q}$的结构为`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)O)[C@]4(C([C@H]3C)=O)O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`。具有顺式邻二醇结构。说法2错误](1)</Checkpoint>

在乙酸酐作用下$\bf{Q}$新产生的羟基被转化为乙酸酯，由于具有邻二醇结构，另一羟基可以进攻酯基，产生五元环，得到$\bf{R}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H]4[C@]5(C([C@H]3C)=O)O[C@](O)(C)O[C@]5(C(F)(F)F)OC(C)4C)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`，其中存在与三个氧原子成键的碳原子。

<Checkpoint>[$\bf{R}$的结构为`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H]4[C@]5(C([C@H]3C)=O)O[C@](O)(C)O[C@]5(C(F)(F)F)OC(C)4C)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`，其中存在与三个氧原子成键的碳原子。说法3正确](1)</Checkpoint>

在碱作用下，原酸酯上羟基氢被拔除，原酸酯分解产生中间体$\bf{Y1}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)[O-])[C@]4(C([C@H]3C)=O)OC(C)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`，随后氧上的负电荷进攻碳碳键，发生逆Aldol反应，打开五元环产生烯醇$\bf{Y2}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)OC(C(F)(F)F)=O)C(OC(C)=O)=C([C@H]3C)[O-])[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`，有3个环。烯醇负离子进攻三氟乙酸酯氧所连的碳原子，产生三元环，离去三氟乙酸根，产生$\bf{X}$。

<Checkpoint>[$\bf{Y2}$的结构为`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)OC(C(F)(F)F)=O)C(OC(C)=O)=C([C@H]3C)[O-])[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`，有3个环。说法4正确](1)</Checkpoint>

说法1，3，4正确，选N。

<MultiModal>![$\bf{Q}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)O)[C@]4(C([C@H]3C)=O)O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`；$\bf{R}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H]4[C@]5(C([C@H]3C)=O)O[C@](O)(C)O[C@]5(C(F)(F)F)OC(C)4C)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`；$\bf{Y1}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)O[C@@]4(C(F)(F)F)[O-])[C@]4(C([C@H]3C)=O)OC(C)=O)[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`；$\bf{Y2}$：`C[Si](C)(O[C@]1(C[C@H]2C)C([C@@]3([C@]([H])([C@H](C(C)(C)OC(C(F)(F)F)=O)C(OC(C)=O)=C([C@H]3C)[O-])[C@@H]2O[Si](C)(C)C(C)(C)C)O[Si](C)(C)C)=CC(C1)=O)C`](/media/uploads/fc166431-eabb-42d1-b265-b1fd4c765d65.png)</MultiModal>