The erythromycins, discovered and isolated in the early 1950s, are the best-known members of the clinically important macrolide class of antibiotics. The 14-membered macrolactone core imbedded in these natural products has inspired new synthetic methods for the construction of large ring lactones, beginning with the landmark synthesis of erythronolide B by the Corey group in 1978. During these ...

P rotecting groups have a long history in synthetic chemistry 1. A protecting group is covalently attached to one functional group to block its reactivity while a second functional group undergoes a chemical transformation, after which the protecting group is then removed (Fig. 1a). The use of protecting groups requires both protection and deprotection steps, so efficiency considerations dictat...

Propargyl esters are employed as effective protecting groups for the carboxyl group during solution-phase peptide synthesis. The propargyl ester groups can be introduced onto free amino acids by treating them with propargyl alcohol saturated with HCl. The reaction between propargyl groups and tetrathiomolybdate is exploited to deblock the propargyl esters. The removal of the propargyl group wit...