tert-Butyl 5'-hydroxy-2'-(methylthio)-6'-oxo-6'H-spiro[cyclohexane-1,9'-pyrazino[1',2':1,5]pyrrolo[2,3-d]pyrimidine]-7'(8'H)-carboxylate

tert-Butyl 5'-hydroxy-2'-(methylthio)-6'-oxo-6'H-spiro[cyclohexane-1,9'-pyrazino[1',2':1,5]pyrrolo[2,3-d]pyrimidine]-7'(8'H)-carboxylate