rrr_asd

Unfortunately, the Lewis acid as a catalyst is not suitable. I tried to find information on this issue, but found reactions required or Lewis acid or heat. I think, it would be better if I tell you more about the problem. I'm looking for the substance non-biological origin, that have a spiral form, and can also compresses and decompresses as spring. Rings like a coumarin will open in a basic environment. They must to unclench my spring. I need some group that will form a cycle in acidic environment, but will not change in the basic environment.

Hello! I need a cyclization reaction which goes in acidic environment. But that substance should not react in a basic environment. Thanks in advance.

edit by mod - I have placed answers in spoiler - please try not to give direct answers to homework questions