(3RS,3aSR,6aRS)-Hexahydrofuro[2,3-b]furan-3-yl (1S,2R)-3-[{[2-(acetylamino)-1,3-benzothiazol-6-yl]sulfonyl}(isobutyl)amino]-1-benzyl-2-hydroxypropylcarbamate AIDS-181338 AIDS181338