Question

Amine group protection during peptide synthesis can be accomplished by converting the amine to

• A. 9 - Fluorenylmethylcarbamate
• B. 1,3 Dithiane
• C. Tetrahydropyranyl ether
• D. Dimethylacetal

Answer 1

The Correct Option is A

When synthesizing peptides, the protection of functional groups is critical to prevent undesirable reactions. One of the most common functional groups that require protection is the amine group present in amino acids. There are specific protecting groups for amines used during peptide synthesis. Let's evaluate the given options to understand which can be used for protecting the amine group.

1. 9 - Fluorenylmethylcarbamate (Fmoc): This is widely used as a temporary protecting group for amines in peptide synthesis. The Fmoc group is easy to attach to amines and can be selectively removed in the presence of other protecting groups by treatment with a base such as piperidine. Hence, this is the correct answer.
2. 1,3 Dithiane: This is typically used for the protection of carbonyl groups through the formation of dithianes but is not suitable for amine protection.
3. Tetrahydropyranyl ether (THP): This is primarily used for the protection of alcohols and not for amine protection.
4. Dimethylacetal: This compound is used in the protection of carbonyl groups by forming acetals. It has no relevance to amine protection.

Conclusion: Among the given options, 9 - Fluorenylmethylcarbamate is the correct choice for protecting an amine group during peptide synthesis.

The Fmoc group is one of the two most common protecting groups for amines, the other being Boc (tert-butyloxycarbonyl). The choice between Fmoc and Boc depends on the specific requirements of the synthesis route, like the stability of intermediates and the conditions available for deprotection.

Tip: Remember that Fmoc protection can be easily reversed under mild basic conditions, making it an ideal choice when gentle deprotection is required.