Infer the final product $\bf X$ with higher symmetry, and calculate the quotient of its relative molecular mass (rounded to two decimal places) and its molecular point group order.

Note: Identical substituents in $\bf X$ are regarded as spheres of the same size.


<MultiModal>![The following is the synthetic route of $\bf X$:
The raw material is O=C(C#C[Si](C(C)C)(C(C)C)C(C)C)C#C[Si](C)(C)C; the first reaction condition is [H]C#C[Si](CC)(CC)CC, BuLi, THF, 0 degrees Celsius for 3 hours; the second reaction condition is 1 M NaOH, MeOH, THF, room temperature for 1 hour; the third reaction condition is BuLi, THF, -78 degrees Celsius for 10 minutes, then add MeI and gradually raise to room temperature; the fourth reaction condition is CuCl, TMEDA, DCM, exposed to air at room temperature for 5 hours; the fifth reaction condition is $\rm K_2CO_3$, MeOH, THF, room temperature for 2.5 hours; the sixth reaction condition is CuCl, TMEDA, DCM, exposed to air at room temperature for 18 hours; the seventh reaction condition is TBAF, wet THF, -15 degrees Celsius for 2.5 hours; the eighth reaction condition is CuCl, TMEDA, DCM, exposed to air at room temperature for 3 hours](/media/uploads/f794aeb1-b184-4c8f-ba7b-5c2cd9008014.png)</MultiModal>
推断具有较高对称性的最终产物$\bf X$，计算其相对分子质量（保留至小数点后第二位）与其分子点群阶数之商。

注意：$\bf X$中相同的取代基视作大小一致的小球。


<MultiModal>![以下为$\bf X$的合成路线：
原料为O=C(C#C[Si](C(C)C)(C(C)C)C(C)C)C#C[Si](C)(C)C；第一步反应条件为[H]C#C[Si](CC)(CC)CC、BuLi、THF、0摄氏度反应3小时；第二步反应条件为1 M NaOH、MeOH、THF、室温反应1小时；第三步反应条件为BuLi、THF、-78摄氏度反应10分钟，然后加入MeI逐渐升至室温；第四步反应条件为CuCl、TMEDA、DCM、暴露于空气中室温反应5小时；第五步反应条件为$\rm K_2CO_3$、MeOH、THF、室温反应2.5小时；第六步反应条件为CuCl、TMEDA、DCM、暴露于空气中室温反应18小时；第七步反应条件为TBAF、湿的THF、-15摄氏度反应2.5小时；第八步反应条件为CuCl、TMEDA、DCM、暴露于空气中室温反应3小时](/media/uploads/f794aeb1-b184-4c8f-ba7b-5c2cd9008014.png)</MultiModal>
All other options are incorrect.
38.37
19.18
7.67
65.07
65.58
37.79
136.67
47.37
16.42
28.18
86.39
68.37
9.67
12.37
97.18
74.67
其他选项均不正确
38.37
19.18
7.67
65.07
65.58
37.79
136.67
47.37
16.42
28.18
86.39
68.37
9.67
12.37
97.18
74.67
The first step is deprotonation of the terminal alkyne, followed by addition of the alkynyl anion to the carbonyl group and subsequent workup to afford a tertiary alcohol.

<MultiModal>![$\bf A$: O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[Si](C)(C)C](/media/uploads/60d221f9-3eca-40bb-8e46-c3188bb7a396.png)</MultiModal>

<Checkpoint>[$\bf A$ is O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[Si](C)(C)C](1)</Checkpoint>

The second step involves relatively mild conditions for the removal of the silyl group. Since there is a stronger deprotection step later, only -TMS is removed in this step.

<MultiModal>![$\bf B$: O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[H]](/media/uploads/1af87aeb-9f11-43cb-9d77-03be5fdd9928.png)</MultiModal>

<Checkpoint>[$\bf B$ is O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[H]](1)</Checkpoint>

In the third step, BuLi deprotonates the compound. Since the next step is a typical oxidative coupling of alkynes, and the acidity of the alcohol hydroxyl group is stronger than that of the alkynyl hydrogen, the alcohol hydroxyl group is preferentially deprotonated and undergoes substitution with -Me, and the alkyne does not undergo substitution.

<MultiModal>![$\bf C$: [H]C#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](/media/uploads/5e8268ad-faeb-4d02-a973-7fcdc05caf60.png)</MultiModal>

<Checkpoint>[$\bf C$ is [H]C#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](1)</Checkpoint>

In the fourth step, two molecules of $\bf C$ undergo oxidative coupling.

<MultiModal>![$\bf D$: CO[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#CC#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](/media/uploads/1f158f5f-5155-46ef-885c-28812897c56a.png)</MultiModal>

<Checkpoint>[$\bf D$ is CO[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#CC#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](1)</Checkpoint>

In the fifth step, the more difficult to remove TES group is removed with a longer reaction time.

<MultiModal>![$\bf E$: [H]C#C[C@@](C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#C[C@@](C#C[H])(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](/media/uploads/2dbfc7e2-5efc-4d10-9158-e300d96a872a.png)</MultiModal>

<Checkpoint>[$\bf E$ is [H]C#C[C@@](C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#C[C@@](C#C[H])(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](1)</Checkpoint>

In the sixth step, two molecules of $\bf E$ undergo oxidative coupling to form the square $\bf F$.

<MultiModal>![$\bf F$: CC([Si](C#CC(C#CC#CC(C#CC#CC1(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#CC(C#CC#C1)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(C(C)C)C(C)C)C](/media/uploads/74af56d3-0411-4aba-bb97-0497517fe7f3.png)</MultiModal>

<Checkpoint>[$\bf F$ is CC([Si](C#CC(C#CC#CC(C#CC#CC1(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#CC(C#CC#C1)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(C(C)C)C(C)C)C](1)</Checkpoint>

In the seventh step, the most difficult to remove TIPS group is removed under the action of TBAF.

<MultiModal>![$\bf G$: [H]C#CC(C#CC#CC(C#CC#CC1(OC)C#C[H])(OC)C#C[H])(OC)C#CC#CC(C#CC#C1)(OC)C#C[H]](/media/uploads/6406350f-8d9b-4ef7-b65a-068275f34eda.png)</MultiModal>

<Checkpoint>[$\bf G$ is [H]C#CC(C#CC#CC(C#CC#CC1(OC)C#C[H])(OC)C#C[H])(OC)C#CC#CC(C#CC#C1)(OC)C#C[H]](1)</Checkpoint>

The eighth step is oxidative coupling to form the expanded cubane $\bf X$.

<MultiModal>![$\bf X$的结构可以看作立方烷的每条边由三根碳碳单键和两根三键交替连接替代，每个顶点上的氢原子由甲氧基替代而成](/media/uploads/b8780b5e-7273-4989-b741-00e4abf0550b.png)</MultiModal>

<Checkpoint>[$\bf X$ has a structure similar to cubane](1)</Checkpoint>

The molecular formula of $\bf X$ is $\rm C_{64}H_{24}O_8$, the molecular weight is 920.91, belongs to the $\rm O_h$ point group, is a group of order 48, the quotient is 19.18, choose C.

<Checkpoint>[The quotient of the molecular weight of $\bf X$ and the group order is 19.18](1)</Checkpoint>
第一步为端炔被攫氢，炔基负离子对羰基进行加成后处理得到叔醇。

<MultiModal>![$\bf A$: O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[Si](C)(C)C](/media/uploads/60d221f9-3eca-40bb-8e46-c3188bb7a396.png)</MultiModal>

<Checkpoint>[$\bf A$为O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[Si](C)(C)C](1)</Checkpoint>

第二步为比较弱的脱去硅基的条件，由于后续还有更强的脱除步骤，故这一步仅脱去-TMS。

<MultiModal>![$\bf B$: O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[H]](/media/uploads/1af87aeb-9f11-43cb-9d77-03be5fdd9928.png)</MultiModal>

<Checkpoint>[$\bf B$为O[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#C[H]](1)</Checkpoint>

第三步BuLi攫氢，由于下一步是典型的炔烃的氧化偶联，醇羟基酸性强于炔基氢，故醇羟基优先被攫氢并发生取代上-Me，炔烃不发生取代。

<MultiModal>![$\bf C$: [H]C#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](/media/uploads/5e8268ad-faeb-4d02-a973-7fcdc05caf60.png)</MultiModal>

<Checkpoint>[$\bf C$为[H]C#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](1)</Checkpoint>

第四步两分子的$\bf C$发生氧化偶联。

<MultiModal>![$\bf D$: CO[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#CC#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](/media/uploads/1f158f5f-5155-46ef-885c-28812897c56a.png)</MultiModal>

<Checkpoint>[$\bf D$为CO[C@](C#C[Si](C(C)C)(C(C)C)C(C)C)(C#C[Si](CC)(CC)CC)C#CC#C[C@@](C#C[Si](CC)(CC)CC)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](1)</Checkpoint>

第五步在更长的反应时间下脱去更难脱的TES基团。

<MultiModal>![$\bf E$: [H]C#C[C@@](C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#C[C@@](C#C[H])(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](/media/uploads/2dbfc7e2-5efc-4d10-9158-e300d96a872a.png)</MultiModal>

<Checkpoint>[$\bf E$为[H]C#C[C@@](C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#C[C@@](C#C[H])(OC)C#C[Si](C(C)C)(C(C)C)C(C)C](1)</Checkpoint>

第六步两分子的$\bf E$发生氧化偶联形成正方形的$\bf F$。

<MultiModal>![$\bf F$: CC([Si](C#CC(C#CC#CC(C#CC#CC1(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#CC(C#CC#C1)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(C(C)C)C(C)C)C](/media/uploads/74af56d3-0411-4aba-bb97-0497517fe7f3.png)</MultiModal>

<Checkpoint>[$\bf F$为CC([Si](C#CC(C#CC#CC(C#CC#CC1(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(OC)C#CC#CC(C#CC#C1)(OC)C#C[Si](C(C)C)(C(C)C)C(C)C)(C(C)C)C(C)C)C](1)</Checkpoint>

第七步在TBAF作用下脱去最难脱的TIPS基团。

<MultiModal>![$\bf G$: [H]C#CC(C#CC#CC(C#CC#CC1(OC)C#C[H])(OC)C#C[H])(OC)C#CC#CC(C#CC#C1)(OC)C#C[H]](/media/uploads/6406350f-8d9b-4ef7-b65a-068275f34eda.png)</MultiModal>

<Checkpoint>[$\bf G$为[H]C#CC(C#CC#CC(C#CC#CC1(OC)C#C[H])(OC)C#C[H])(OC)C#CC#CC(C#CC#C1)(OC)C#C[H]](1)</Checkpoint>

第八步氧化偶联形成扩张立方烷$\bf X$。

<MultiModal>![$\bf X$的结构可以看作立方烷的每条边由三根碳碳单键和两根三键交替连接替代，每个顶点上的氢原子由甲氧基替代而成](/media/uploads/b8780b5e-7273-4989-b741-00e4abf0550b.png)</MultiModal>

<Checkpoint>[$\bf X$具有类似立方烷的结构](1)</Checkpoint>

$\bf X$的分子式为$\rm C_{64}H_{24}O_8$，分子量为920.91，属$\rm O_h$点群，为48阶群，商为19.18，选C。

<Checkpoint>[$\bf X$的分子量与群阶数之商为19.18](1)</Checkpoint>