Highly Optimized Synthesis Procedures were Available

3 Highly Optimized Synthesis Procedures were Available 

The preparation of peptides and nucleotides involves the iterative repetition of three simple steps monomer activation, coupling to the growing chain, and deprotection to unmask a new reactive terminus. The arithmetical demon of linear syntheses, whereby the overall yield decreases exponentially with any loss in yield for each cycle, had forced chemists to perfect these reactions to the point of being practically quantitative. The availability of such robust protocols was a necessary prerequisite for combinatorial chemistry. Outside the peptide and nucleotide areas, synthesis of a library is often far less time consuming than the development of optimized reaction conditions. 

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