(4R,12aS)-7-(Benzyloxy)-4-methyl-6,8-dioxo-3,4,6,8,12,12a-hexahydro-2H-pyrido[1',2':4,5]pyrazino[2,1-b][1,3]oxazine-9-carboxylic Acid is an antiviral agent and a Dolutegravir (D528800) intermediate. Dolutegravir is a second generation HIV-1 integrase strand transfer inhibitor.