Acylamino special

From the initial evaluation of the large number of 14-acylamino- and 14-alkylamino-codeinones and morphinones synthesised in the Reckitt and Colman programme, it became clear that the C14 side chains of particular interest were those with an aryl group joined to C14 by an alkyl group of two to four carbon atoms with three carbon chain compounds having special qualities. Lewis et al. [14] revealed... 

Racemization during the synthesis of peptides is a complex problem. The diversity of possible courses followed in the process is compounded by the individuality of the amino acids. This was already shown on the example of S-alkyl-cysteine residues which lose chiral purity by a special mechanism even if protected by a urethane-type protecting group that prevents racemization in other acylamino acids. The opposite end of the scale is represented by proline... 

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