2Bz4OH5Naphth-O-N-IndanBuCONH2 isostere 5-[2(S)-[(1,1-Dimethylethyl)aminocarbonyl]-4(S)-(2-naphthalenyloxy)-1-pyrrolidinyl]-4(S)-hydroxy-N-(2(R)-hydroxy-1(S)-indanyl)-2(R)-(phenylmethyl)pentanamide AIDS-006759 AIDS006759 L-735,524 analog