(1S,2S,3S,4R)-4-[(diaminomethylidene)amino]-3-(1-acetamido-2-ethylbutyl)-2-hydroxycyclopentane-1-carboxylic acid

3(r)-[1(s)-acetamido-2-ethylbutyl]-4(r)-guanidino-2(s)- hydroxycyclopentane-1(s)-carboxylic acid ; (1s,2s,3r,4r)-3-(1-acetamido-2-ethylbutyl)-4-guanidino-2-hydroxycyclopentanecarboxylic acid ; peramivir ; (1s,2s,3s,4r)-3-[(1s)-1-acetamido-2-ethylbutyl]-4-[(diaminomethylene)amino]-2-hydroxycyclopentanecarboxylic acid