[Sis290025]

Diagram all atoms of tryptophan as the butyl ester of N-acetyl-D-tryptophan.

I drew out N-acetyl-D-tryptophan, but I do not understand the wording of the question. What is meant by "butyl ester of N-acetyl-D-tryptophan"? Am I to imagine that N-acetyl-D-tryptophan is a participant in a chemical reaction that will yield an ester version of it?

Thank you.

[bromidewind]

Maybe the butyl ester is functioning as a protecting group for the amino acid?

[Doc Oc]

The question is oddly worded, that's for sure.  But it's just saying to draw N-acetyl-tryptophan with a tert-butyl ester instead of the free carboxylic acid.

[discodermolide]

Diagram all atoms of tryptophan as the butyl ester of N-acetyl-D-tryptophan.

I drew out N-acetyl-D-tryptophan, but I do not understand the wording of the question. What is meant by "butyl ester of N-acetyl-D-tryptophan"? Am I to imagine that N-acetyl-D-tryptophan is a participant in a chemical reaction that will yield an ester version of it?

Thank you.

Just draw N-acetyl-D-Tryptophan and to the carboxylic acid draw a 4 carbon chain, C4H9 on the oxygen atom of the acid OH group, i.e. RCOOCH2CH2CH2CH3, where R is the rest of the molecule