4. Propose a selective dipeptide synthesis for Ala-Cys (below). (2 pts) Me H HN OH SH a. Draw the structures for the starting amino acids (AA), reagents, and intermediate products, do not abbreviate to letters. b. Recall that the synthesis requires protecting groups for each AA. You have two choices of carbamate protecting groups for amines and two choices to protect the acid: O-benzyl group or use a PS bead. Start with a protected acid on the right hand residue and reactg its amine with the acid of a protected amine on the left residue - see Ch. 27C). c. All protecting groups should be removed at the end of the synthesis using the reagents given in in the notes