Is it just for historical reasons? Because the first person who did it decided to attach the C-terminus to the solid support?

Or are there chemical reasons why it would be impossible to proceed in the opposite direction?

  • 1
    $\begingroup$ It's not impossible, it's just a lot harder and much more research has been put into the C → N version. $\endgroup$
    – Jan
    Jun 25, 2015 at 9:17

1 Answer 1


The reasons are

  1. The use of an acylating agent in excess (e. g. acetic anhydride or N-acetyl imidazole) drives the reaction forward.
  2. UNCAs (urethane-type protected N-carboxy anhydrides (e. g. Fmoc, Z, Boc, ...)) can be used. They prevent racemization of the amino acid, that it is attached to.

But there are (despite of ribosomes themselves) also instances, where N -> C directionality was applied:


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.