Planning a synthesisProtect one amine and one acid, couple, then deprotect, choosing groups that come off one at a time. Draw every intermediate on the way.

HGlyAlaOH, step by step: Couple BocGlyOH with HAlaOBn, then take both groups off. Draw the product of each of the three steps.

Plan HAlaGlyOH yourself: Make HAlaGlyOH and nothing else. Draw the two protected amino acids you start from, the coupled dipeptide and the final product.

Two groups off in one step: A Cbz group and a benzyl ester are both cut by hydrogen on palladium. Draw everything one hydrogenolysis gives from CbzAlaPheOBn.

One group off, the other kept: Acid takes off Boc and leaves a benzyl ester: the two are orthogonal. Use it to grow BocPheGlyOBn by one residue at its N-terminus.

A tripeptide from the C-terminus: Make HGlyAlaPheOH from BocGlyOH, BocAlaOH and HPheOBn. Start from the C-terminus, which stays protected to the end.

HValLeuOH with Cbz and a methyl ester: A methyl ester does not come off with hydrogen, so this route needs one more step. Draw the coupled dipeptide and each deprotection.

Draw the products and intermediates of a peptide synthesis, from protecting groups to DCC coupling, and follow two slide shows. The exercises need JavaScript, because every drawing is checked in your browser.

Why protect — heat two amino acids, and count what forms

Protecting groups — put them on, take them off

Coupling with DCC — activate the acid, then form the amide

Planning a synthesis — protect, couple, deprotect, in the right order

Builder — type a sequence, see the molecule

Cheatsheet — every group, how it goes on and comes off

Talks — two slide shows, mechanisms included

About — what the site is, and how to cite it

Our other tools

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inchi.cheminfo.org — InChI and InChIKey from a structure, in the browser.

vcl.cheminfo.org — Combine a core and fragments into a screened library.

smiles.cheminfo.org — Draw a structure, read its SMILES, learn the notation.

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openbabel.cheminfo.org — Convert a structure between any pair of chemical file formats.

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metabo.nmrium.com — Turn a batch of NMR spectra into a map of your samples.

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elucidation.cheminfo.org — A structure from a 1H NMR spectrum and a formula.

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equilibrium.cheminfo.org — Chemical equilibria: pH, speciation and titration curves.

polycarp.cheminfo.org — Predict the microstructure of a radical copolymerisation.

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wikidata.cheminfo.org — The chemistry of Wikipedia’s infoboxes, searchable by structure.

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atoms.cheminfo.org — Electrons, neutrons, Lewis structures and oxidation states.

moles.cheminfo.org — Balance a reaction, and work out its mass composition.

inorganic.cheminfo.org — Name an inorganic compound, and write its formula.

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vibrations.cheminfo.org — IR and Raman spectra computed in the browser.

draw.cheminfo.org — Journal-grade structures, in an SVG that keeps the chemistry.

plate.cheminfo.org — Read a TLC plate, a gel or a blot from a photograph.

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