<MultiModal>![The figure shows an organic reaction, the reactant is OCC1=C(CC2(C)C(CC(C)(C)CC2=O)=O)C=CC=C1, the condition is adding $\rm NaH$, the product is unknown](/media/uploads/91cf47f4-07d7-4d5f-a50e-1297ca906302.png)</MultiModal>

For the reaction shown in the figure, which of the following statements is correct:
<MultiModal>![图为一个有机反应，反应物为OCC1=C(CC2(C)C(CC(C)(C)CC2=O)=O)C=CC=C1，条件为加入$\rm NaH$，生成物未知](/media/uploads/91cf47f4-07d7-4d5f-a50e-1297ca906302.png)</MultiModal>

对于图示反应，下列说法正确的是：
The first step of this reaction generates an enolate intermediate.
The first step of this reaction is the nucleophilic attack of a hydride ion on the carbonyl group.
The product has three six-membered rings.
The reaction process involves a six-membered ring carbanion intermediate.
The product is a sodium salt.
The product contains a six-membered ring lactone.
The product contains an eight-membered ring ether.
The product can react with metallic sodium.
None of the above options are correct.
该反应第一步生成烯醇负离子中间体
该反应第一步氢负离子对羰基亲核进攻
产物有三个六元环
反应过程中存在六元环碳负离子中间体
产物为一种钠盐
产物中含有一个六元环的内酯
产物中含有一个八元环的醚
产物能与金属钠发生反应
以上选项都不对
The reaction intermediates and products are shown in the figure: <MultiModal>![Reaction intermediates and products](/media/uploads/d5e57799-95fa-44a0-b314-5daaa2b4e6e8.png)</MultiModal>
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Sodium hydride is a strong base but has weak nucleophilicity, so the first step reacts with the most active proton, namely the hydroxyl hydrogen, to generate the oxyanion [O-]CC1=CC=CC=C1CC2(C)C(CC(C)(C)CC2=O)=O, options A and B are incorrect.
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<Checkpoint>[Generation of oxyanion [O-]CC1=CC=CC=C1CC2(C)C(CC(C)(C)CC2=O)=O](1)</Checkpoint>
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Subsequently, the oxyanion attacks the carbonyl group, generating the tetrahedral intermediate O=C1[C@]2(C)CC3=CC=CC=C3CO[C@@]([O-])2CC(C)(C)C1.
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<Checkpoint>[Generation of tetrahedral intermediate O=C1[C@]2(C)CC3=CC=CC=C3CO[C@@]([O-])2CC(C)(C)C1](1)</Checkpoint>
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The next reaction of the tetrahedral intermediate is carbon-carbon bond cleavage. The cleaved carbon-carbon bond should generate the most stable carbanion. Option D is correct. The carbon-carbon bond connecting the carbonyl group and the quaternary carbon atom cleaves, and the generated carbanion is relatively stable due to the electron-withdrawing effect of another adjacent carbonyl group. The carbanion is O=C(CC(C)(C)C1)[C-](C)CC2=CC=CC=C2COC1=O.
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<Checkpoint>[Generation of carbanion O=C(CC(C)(C)C1)[C-](C)CC2=CC=CC=C2COC1=O](1)</Checkpoint>
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In the workup process, the carbanion abstracts a proton to obtain the product. The product structure is O=C(CC(C)(C)C1)C(C)CC2=CC=CC=C2COC1=O, which is an electrically neutral product with only one six-membered ring, a 11-membered ring lactone and an ether bond, so all options are incorrect.
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<Checkpoint>[Product structure is O=C(CC(C)(C)C1)C(C)CC2=CC=CC=C2COC1=O](1)</Checkpoint>

<Checkpoint>[The product molecule has an 11-membered ring structure, which contains an ester group and an ether bond](1)</Checkpoint>
反应的中间体和产物如图：<MultiModal>![反应的中间体和产物](/media/uploads/d5e57799-95fa-44a0-b314-5daaa2b4e6e8.png)</MultiModal>
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氢化钠是强碱但亲和性弱，因此第一步与最活泼的质子即羟基氢反应，生成氧负离子[O-]CC1=CC=CC=C1CC2(C)C(CC(C)(C)CC2=O)=O，选项A，B错误。\
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<Checkpoint>[生成氧负离子[O-]CC1=CC=CC=C1CC2(C)C(CC(C)(C)CC2=O)=O](1)</Checkpoint>\
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随后氧负离子进攻羰基，生成四面体中间体O=C1[C@]2(C)CC3=CC=CC=C3CO[C@@]([O-])2CC(C)(C)C1。\
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<Checkpoint>[生成四面体中间体O=C1[C@]2(C)CC3=CC=CC=C3CO[C@@]([O-])2CC(C)(C)C1](1)</Checkpoint>\
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四面体中间体的下一步反应是碳碳键断裂，断裂的碳碳键应当生成最稳定的碳负离子，选项D正确。连接羰基与季碳原子的碳碳键断裂，生成的碳负离子由于邻近另一个羰基的吸电子而较为稳定。碳负离子为O=C(CC(C)(C)C1)[C-](C)CC2=CC=CC=C2COC1=O。\
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<Checkpoint>[生成碳负离子O=C(CC(C)(C)C1)[C-](C)CC2=CC=CC=C2COC1=O](1)</Checkpoint>\
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在后处理过程中碳负离子攫取质子，得到产物。产物结构为O=C(CCC1)C(C)CC2=CC=CC=C2COC1=O，是电中性产物，只有一个六元环，含11元环的内酯与醚键，所以所有选项都是错误的。\
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<Checkpoint>[产物结构为O=C(CC(C)(C)C1)C(C)CC2=CC=CC=C2COC1=O](1)</Checkpoint>

<Checkpoint>[产物分子有一个有11元环结构，其中包含酯基与醚键](1)</Checkpoint>