Radical cyclization usually exhibits certain regioselectivity.

<MultiModal>![C=CCCC[C]([H])[H], This carbon radical will spontaneously form a cyclic structure; attempt to predict the product](/media/uploads/34603918-e3be-46b0-83b2-70f937356701.png)</MultiModal>

<MultiModal>![C=CCCC([C]([H])[H])=O, This carbon radical will spontaneously form a cyclic structure; attempt to predict the product](/media/uploads/4e26019d-5e1f-4fc9-b331-14969097992d.png)</MultiModal>

Please attempt to predict the products of the above two radical cyclization reactions, respectively, and provide a reasonable explanation.
自由基关环通常会具有一定的区域选择性。

<MultiModal>![C=CCCC[C]([H])[H],该碳自由基会自发形成环状结构，尝试对产物进行预测](/media/uploads/34603918-e3be-46b0-83b2-70f937356701.png)</MultiModal>

<MultiModal>![C=CCCC([C]([H])[H])=O,该碳自由基会自发形成环状结构，尝试对产物进行预测](/media/uploads/4e26019d-5e1f-4fc9-b331-14969097992d.png)</MultiModal>


请尝试分别预测以上两个自由基成环反应的产物，并给出合理的解释。
<MultiModal>![[H][C]([H])C1CCCC1](/media/uploads/6906dee2-924e-4891-ab39-0f4dc8c64cd3.png)</MultiModal>

<MultiModal>![[H][C]([H])C(CC1)CC1=O](/media/uploads/4d184b67-10b7-40cc-8367-2a5b4109dd6a.png)</MultiModal>

Forming five-membered ring and five-membered ring products respectively
<MultiModal>![[H][C]1CCCCC1](/media/uploads/cc457726-7fe1-4326-aafe-b73cabc57909.png)</MultiModal>

<MultiModal>![[H][C]([H])C(CC1)CC1=O](/media/uploads/4d184b67-10b7-40cc-8367-2a5b4109dd6a.png)</MultiModal>

Six-membered ring and five-membered ring products were formed respectively.
<MultiModal>![[H][C]([H])C1CCCC1](/media/uploads/6906dee2-924e-4891-ab39-0f4dc8c64cd3.png)</MultiModal>

<MultiModal>![[H][C]1CCC(CC1)=O](/media/uploads/9e8c95cb-c76f-4112-957d-d872b7e2ad0a.png)</MultiModal>

Five-membered ring and six-membered ring products were formed respectively.
<MultiModal>![[H][C]1CCCCC1](/media/uploads/cc457726-7fe1-4326-aafe-b73cabc57909.png)</MultiModal>

<MultiModal>![[H][C]1CCC(CC1)=O](/media/uploads/9e8c95cb-c76f-4112-957d-d872b7e2ad0a.png)</MultiModal>

Six-membered ring and six-membered ring products are formed respectively.
<MultiModal>![[H][C]([H])C1CCCC1](/media/uploads/6906dee2-924e-4891-ab39-0f4dc8c64cd3.png)</MultiModal>

<MultiModal>![[H][C]([H])C(CC1)CC1=O](/media/uploads/4d184b67-10b7-40cc-8367-2a5b4109dd6a.png)</MultiModal>

分别形成了五元环和五元环产物

<MultiModal>![[H][C]1CCCCC1](/media/uploads/cc457726-7fe1-4326-aafe-b73cabc57909.png)</MultiModal>

<MultiModal>![[H][C]([H])C(CC1)CC1=O](/media/uploads/4d184b67-10b7-40cc-8367-2a5b4109dd6a.png)</MultiModal>

分别形成了六元环和五元环产物
<MultiModal>![[H][C]([H])C1CCCC1](/media/uploads/6906dee2-924e-4891-ab39-0f4dc8c64cd3.png)</MultiModal>

<MultiModal>![[H][C]1CCC(CC1)=O](/media/uploads/9e8c95cb-c76f-4112-957d-d872b7e2ad0a.png)</MultiModal>

分别形成了五元环和六元环产物
<MultiModal>![[H][C]1CCCCC1](/media/uploads/cc457726-7fe1-4326-aafe-b73cabc57909.png)</MultiModal>

<MultiModal>![[H][C]1CCC(CC1)=O](/media/uploads/9e8c95cb-c76f-4112-957d-d872b7e2ad0a.png)</MultiModal>

分别形成了六元环和六元环产物
Generally, the formation of five-membered rings via radicals is faster than six-membered rings, so the first molecule will yield a five-membered ring product.

<Checkpoint>[Generally, the formation of five-membered rings via radicals is faster than six-membered rings, so the first molecule will yield a five-membered ring product](1)</Checkpoint>

The presence of a carbonyl group stabilizes the radical, improves the reversibility of ring closure, and facilitates the formation of the more stable six-membered ring.

<Checkpoint>[The presence of a carbonyl group stabilizes the radical, improves the reversibility of ring closure, and facilitates the formation of the more stable six-membered ring](1)</Checkpoint>

The presence of a carbonyl group causes the two carbon atoms to adopt an $\displaystyle \mathbf { s p } ^ { 2 }$ hybridization state, resulting in increased rigidity and making orbital overlap in the five-membered ring transition state more difficult.

<Checkpoint>[The presence of a carbonyl group causes the two carbon atoms to adopt an $\displaystyle \mathbf { s p } ^ { 2 }$ hybridization state, resulting in increased rigidity and making orbital overlap in the five-membered ring transition state more difficult](1)</Checkpoint>
一般自由基成五元环比六元环快，因此第一个分子将形成五元环产物

<Checkpoint>[一般自由基成五元环比六元环快，因此第一个分子将形成五元环产物](1)</Checkpoint>

羰基的存在使自由基更加稳定，关环可逆性更好，容易得到更稳定的六元环 

<Checkpoint>[羰基的存在使自由基更加稳定，关环可逆性更好，容易得到更稳定的六元环 ](1)</Checkpoint>

羰基的存在导致两个C原子变为 $\displaystyle \mathbf { s p } ^ { 2 }$ 杂化形式，刚性更加显著，五元环过渡态的轨道重叠较为困难

<Checkpoint>[羰基的存在导致两个C原子变为 $\displaystyle \mathbf { s p } ^ { 2 }$ 杂化形式，刚性更加显著，五元环过渡态的轨道重叠较为困难](1)</Checkpoint>