N-((R)-2-(((7aR,8R)-1,9-dioxo-3,4,6,7a,8,9-hexahydro-1H-azeto[2,1-b][1,4]oxathiepino[6,5-d][1,3]thiazin-8-yl)amino)-1-(4-hydroxyphenyl)-2-oxoethyl)-4-ethyl-2,3-dioxopiperazine-1-carboxamide