CHEM 215 Study Guide - Midterm Guide: Weak Base, Phenylalanine, Tripeptide
Document Summary
21. 2, 21. 8, 23. 3, 23. 6, 15. 8) : laboratory methods for peptide synthesis. Val (a) protection and deprotection steps for c-terminal end (the acid) prot c and deprot c . Ala for convenience, the low ph form of the amino acids are shown, and might assume an adjustment of the ph. Ch3 in preparing the esters, it is assumed that the ph is adjusted to give the neutral organic product (the amine) (b) protection and deprotection steps for n-terminal end (the amine) prot n and deprot n . Ch2ph in preparing the carbamates (the protected form of the amine) it is assumed, and sometimes shown, that a weak base is present, e. g. , (ch3ch2)3n. Ch2ph deprotection gives a carbamic acid, which decarboxylates to give the amine (see below) Goal: preparation of a tripeptide - ala-val-gly (see pka table for structures); one plan might be this: Ch(ch3)2 deprot c gly: h2 / pd-c.
