INHIBITORS OF HIV-1 PROTEINASE CONTAINING 2-HETEROSUBSTITUTED 4-AMINO-3-HYDROXY-5-PHENYLPENTANOIC ACID - SYNTHESIS, ENZYME-INHIBITION, AND ANTIVIRAL ACTIVITY

A convenient procedure for the synthesis of 2-heterosubstituted statine derivatives as novel building blocks in HN-protease inhibitors has been developed. The synthesis starts with protected L-phenylalaninols, which were converted to gamma-amino alpha,beta-unsaturated esters in a one-pot procedure. A highly diastereoseletive epoxidation of the N-protected (E)-enoates, followed by regioselective ring opening of the corresponding 2,3-epoxy esters with a variety of heteronucleophiles, resulted in 2-heterosubstituted statine derivatives. The overall stereochemical outcome of the transformations meets the required configuration of HIV-protease inhibitors. The short, synthetically flexible, and highly diastereoselective synthesis of 2-heterosubstituted statines has enabled a broad derivation, covering the S3, S2, and S1'-S3' sites of the enzyme. In a series of 46 derivatives, several potent inhibitors were obtained with K-i values as low as 3.4 nM and antiviral activity in the lower nanomolar-range. The structural parameters of the compounds which determine the potency of inhibition and selectivity for the viral enzyme are discussed.