Look further down.

[Second question: Retrosynthesis is performed by the cutting method, please give the retrosynthesis analysis]

Li Zheng's eyes widened.

Only then did I understand.

This question is not a loop.

Instead, it is reversed into a loop.

Cut rings.

Cut a complex ring into several large individual rings, then cut the large rings into smaller rings, and so on until you find a simple enough starting material.

Taking cooking as a metaphor is equivalent to throwing a finished dish to the chef to taste, so that he can reverse the practice.

Wonderful is wonderful.

But this is already an organic question at the graduate level.

None of the ICHO international competitions will necessarily be so deep.

Even Li Zheng, who was overprepared, was panicked in the face of such a magic ring.

Of course, how panicked you are, how excited you are.

If it were Shi Yang, how would he feel when faced with this question?

If you think about it, this magic ring is indeed terrifying.

However, the knowledge of problem solving did not exceed the outline of the finals.

Among them, the most critical "Organic Synthesis - Cutting Method" and "Organic Synthesis Route Design" are also just gnawed by myself, and I have occasionally discussed them with Shi Yang before.

Theoretically, you already have all the basic knowledge to understand this question.

It's just that in the face of questions at this level, there is still too little experience and training.

It's like a junior chef who has mastered all the cooking techniques.

But it is still too difficult to throw the Manchu full banquet to him and let him reverse the method according to the taste.

Li Zheng subconsciously looked at Zhou Yi on the stage.

Zhou Yi also found him, and immediately smiled: "It's okay, classmate, if you can't do it, come back and listen carefully, the competition in chemistry competitions is indeed not as fierce as mathematics and physics, but winning the gold medal is not so easy." ”

The training team members were very confused in the face of Zhou Yi's words.

What is the matter with the Math Physics Competition?

Ou Xingzhuo stared at him and lowered his head.

This fat doll seems to mind the matter of collecting Dragon Balls......

Won't it ......

He also turned to look at Li Zheng and felt a little guilty.

I'm sorry, friend.

Li Zheng didn't say much, and quickly returned to his position.

However, instead of sitting down, he picked up his bag.

I pulled out two big empty notebooks and went all the way back to the table.

That's when everyone reacted.

He just came back to get scratch paper.

In the exclamation, Zhou Yi was not angry, but very excited.

"Okay, ambitious!" Zhou Yi held the microphone tightly and was impassioned.

"That's what I said next—chemistry is like life. ”

"There is no key that cannot be broken, but you and I are not knowledgeable enough. ”

"There's no ring that can't be made, it's just that you and I haven't worked hard enough. ”

"Every new reaction is a new scenery. ”

"Each intermediate is our dormant journey. ”

"Every process is reversible. ”

"Only by moving forward bravely, will you not return to the starting point!"

There was no doubt that the students would have applauded again.

It's all chicken soup.

But combined with the chemistry one.

Suddenly it became demonic.

On the other hand, Li Zheng has no doubt.

The ultimate 112x speed has been turned on.

Zhou Chenghuan!

If you are unkind, don't blame me for being unjust.

Obviously, the current experience and knowledge are not enough to break this magic ring.

Then Lao Tzu tried one by one, cutting one key at a time.

Let's fry, fry, fry, stew, stew, simmer, stew, stew and boil one by one.

Countering violence with violence.

The key is coming!

......

Half an hour later, Zhou Yi's speech was nearing its end.

Although Li Zheng didn't hear it, it was actually very exciting.

The first half is chicken soup and poisonous chicken soup, telling everyone about the sweetness and bitterness of chemistry, and with his personal understanding of the ring, the whole process is rippling with magical literary brilliance.

In the second half, he explained in detail the selection rules for entering the provincial team and signing a contract with Jida to ensure that every student knows how to achieve their goals.

From time to time, he glanced at Li Zheng, who was crazy about solving problems, and saw that Li Zheng was so committed and did not give up, and he was also quite appreciative.

It's not just chemistry, it's all about it.

In the end, Zhou Yi even deliberately slowed down the speed of his speech, just to give Li Zheng more time.

At this time, what kind of dragon ball random parking and the like are naturally long gone.

This question, I haven't studied organic in a top chemical school for a few years, so I don't want to give the retrosynthesis step.

This Ou Xingzhuo can explain the structure of the ring clearly, it is a good example.

Li Zheng's side has already fallen into the devil.

This magic ring has been cut countless times like a kaleidoscope nesting doll.

In the microcosm of his chemical meditation, countless possibilities are simulated.

The reality is only half an hour.

But now he is 112 times faster.

Plus 100% of Chemistry Mania and a 50% bonus from the Demon "Enchanted Status".

In just half an hour, it is equivalent to 140 hours of rigidity.

Even Li Zheng has never been so stunned.

Until.

His eyes widened.

It's done!

Five steps.

Cut 10 keys.

Eventually, it was broken down into three ghost things.

It's a ghost, but the core is still a ring.

A six-membered ring, a five-membered ring, and a three-membered ring.

I'm not sure if these three things can be obtained as raw materials.

But each step is possible in chemical meditation.

Ultimately.

"Smack".

Ring, pen down.

Li Zheng sat down in his chair, as if he had just fought an endless war.

Or maybe I had a hearty long dream.

In short, the eyes look at whatever they want.

It's all rings.

On the stage, Zhou Yi saw Li Zheng stop writing, and also made a final speech to wrap up.

"Whether it's the current training camp or the university in the future. ”

"Please keep in mind. ”

"Any competition is not your internal competition, but external competition. ”

"What should really be considered is: how can we be higher than the academic level outside. ”

"You're better than me, not stronger. ”

"Only our entire Chinese chemical collective is strong. ”

"You deserve to be strong. ”

"Thank you. ”

Zhou Yi finished speaking, and bowed steadily to the students in the audience.

All the students stood up consciously and applauded.

For them, the bow is unbearable.

Li Zheng also broke away from the world of the ring.

Zhou Yi's words, isn't that what Shi Yang said?

In the end, it's all your own!

Everyone is a ring, why is this too anxious?

Zhou Yi also looked at Li Zheng, his eyes were full of ring flavor, and he walked off the stage quickly: "Wait two minutes, students, I'll see how this ring cuts." ”

Li Zheng also got up, picked up his answer sheet and greeted Zhou Yi, the ring flavor in his eyes was no less than that of the dean.

"Teacher Zhou, this question is very enjoyable. ”

Zhou Yi only smiled, he didn't believe it, this kid must be pretending again.

Until he took the answer sheet.

Five steps and six diagrams, large rings and small rings, there are shapes.

Zhou Yi also had to taste it seriously, muttering while savoring.

"Yes. ”

"Yes, it's a loop. ”

"Can this also be a ring?"

"Isn't this a loop?"

"Very imaginative ring. ”

"Good ring!"