title: Crown ethers as catalysts of fluoride-anion-mediated reactions in peptide synthesis. Part 1. Protection of tryptophan by benzyloxy-carbonyl and 2,4-dichlorobenzyloxycarbonyl groups.
mesh_terms: D000215:Acylation; D002384:Catalysis; D002722:Chlorobenzenes; D004988:Ethers, Cyclic; D005459:Fluorides; D007659:Ketones; D010455:Peptides / Q000138:chemical synthesis*; D014364:Tryptophan
chemical_list: D002722:Chlorobenzenes; D004988:Ethers, Cyclic; D007659:Ketones; D010455:Peptides; D014364:Tryptophan; D005459:Fluorides