((S)-1-{(1S,2S,4R)-1-Benzyl-4-[(S)-1-((S)-1-formyl-2-methyl-propylcarbamoyl)-2-methyl-propylcarbamoyl]-2-hydroxy-heptylcarbamoyl}-ethyl)-carbamic acid benzyl ester AIDS-050377 AIDS050377 Hydroxyethylene isostere compound with methanol