Look further down.

[Second question: Currently the cut-off method is used for retrosynthesis, please provide a retrosynthetic analysis]

Li Zheng stared.

Only then did I understand.

This question is not a loop.

Instead, it forms a loop in reverse.

Cut the ring.

You need to cut an extremely complex magic ring into several independent large rings, then cut the large ring into small rings, and so on until you find a starting material that is simple and common enough.

Using the metaphor of cooking, it is equivalent to throwing a prepared dish to the cook to taste it and asking him to reversely deduce how to make it.

Wonderful is wonderful.

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

ICHO international competitions may not lead you to such a deep level.

Even Li Zheng, who was extremely prepared, was panicked when faced with such a magical ring.

Of course, no matter how panicked you are, you will naturally be as excited as you are.

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

If you think about it carefully, 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 ones, "Organic Synthesis - Cut-off Method" and "Organic Synthesis Route Design", were the ones I had just read, and I had occasionally discussed them with Shi Yang before.

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

However, facing this level of questions, I still lack experience and training.

It's like a junior cook apprentice who has indeed mastered all cooking techniques.

But it was still too difficult to throw a Man-Han banquet to him and ask him to reversely deduce the recipe based on the taste.

Li Zheng subconsciously looked at Zhou Yi on the stage.

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

The training team members were all very confused when faced with Zhou Yi's remarks.

What’s the matter with the Mathematical Physics Competition?

Ou Xingzhuo glared and lowered his head.

This fat kid seems to be very concerned about getting the Dragon Balls in the achievement set...

Could it be...

He then turned to look at Li Zheng, feeling a little guilty.

Sorry, friend.

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

However, he did not sit down, but picked up his schoolbag.

He took out two empty notebooks and returned to the table.

Only then did everyone react.

He just came back to get scratch paper.

Amid the exclamations, Zhou Yi was not angry, but very excited.

"Okay, you are ambitious!" Zhou Yi held the microphone tightly and spoke impassionedly.

"That's exactly what I said next - chemistry is like life."

"There is no unbreakable bond, it's just that you and I don't know enough."

"There is no link that cannot be achieved, it's just that your and my efforts are not enough."

"Every new reaction is a new scenery."

"Every intermediate is our dormant process."

"Every process is reversible."

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

The students undoubtedly applauded again.

It's obviously all chicken soup.

But combined with chemistry.

Suddenly it became magical.

On the other side, Li Zheng also had no doubts.

The ultimate 112x speed has been turned on.

Zhou Chenghuan!

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

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

Then I will try it one by one and cut it key by key.

Let's fry, stir-fry, deep-fry, stew, stew, steam, and stew one by one.

Fight violence with violence.

Come on!

…

Half an hour later, Zhou Yi's speech was coming to an 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 engaging in chemistry, and combined with his personal understanding of the environment, the whole process is full of magical literary talent.

In the second half, he explained in detail the selection rules for joining the provincial team and signing with Jida, ensuring that every student knew how to achieve their goals.

From time to time, he glanced at Li Zheng who was frantically solving problems. Seeing that Li Zheng was so devoted and didn't give up, he was quite impressed.

Not just chemistry, everything requires this kind of ruthlessness.

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

At this time, the bad issues such as parking the car randomly in Longzhu have naturally passed away.

For this question, if you haven't studied organic matter for several years in a top chemistry college, you can't even think of giving the steps for retrosynthesis.

It would be great if Ou Xingzhuo could clearly explain the structure of the ring.

Li Zheng has already been possessed by the devil.

This magic ring has been cut countless times like a kaleidoscope of matryoshka dolls.

He also simulated countless possibilities in the microscopic world of chemical meditation.

Although the actual time is only half an hour.

But now he is already 112 times faster.

In addition, the chemical mania is 100%, and the 50% bonus provided by the "enchanted state" of the earth demon.

This short half hour is equivalent to 140 hours of hard work.

Even Li Zheng has never been so stunned.

until.

He stared.

Done!

Five steps.

Cut 10 keys.

Eventually it was broken down into three ghosts.

It is said to be a ghost thing, but its core is still a ring.

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

Although I'm not sure these three ghosts can be obtained as raw materials.

But every step is possible in chemical meditation.

finally.

There was a "pop" sound.

The circle is formed and the pen falls.

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

Or maybe I had a long, heartfelt dream.

In short, it doesn’t matter what your eyes are looking at right now.

It's all a circle.

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

"Whether it's training now or college in the future."

"Please remember this."

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

"What we should really consider is: how can we achieve a higher academic level than what is available outside."

"You are better than me, not stronger."

"Only our entire China Chemical Group is stronger."

"You are the one who deserves to be strong."

"thank you all."

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

All the students stood up voluntarily and applauded thunderously.

For them, this bow is unbearable.

Li Zheng also just broke away from the world of Huan.

Aren't Zhou Yi's words exactly what Shi Yang said?

In the end, we are all our own people!

We are all connected, so there is no need to worry about this.

Zhou Yi also looked at Li Zheng, his eyes full of ring smell, and quickly stepped off the stage: "Students, wait for two minutes, let me see how this circumcision goes."

Li Zheng also stood up, picked up his answer sheet and faced Zhou Yi. The smell in his eyes was no less than that of the dean.

"Teacher Zhou, this question is very enjoyable."

Zhou Yi just smiled. He didn't quite believe it. This guy must be pretending again.

Until he took the answer sheet.

Five steps and six pictures, with big rings inside small rings, and it looks pretty.

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

"Can."

"Okay, this is a good idea."

"Can this also form a ring?"

"Isn't this all a piece of cake?"

“Very imaginative ring.”
Chapter completed!