(1R,5S)-(+) -2-oxabicyclo [3.3.0] oct-6-en-3-one [54483-22-6] as Darunavir intermediate (1R,5S)-(+) -2-oxabicyclo [3.3.0] oct-6-en-3-one CAS NO. 54483-22-6Assay:99%e.e 98%MINWater 0.5%MAXSingle impurity 0.5%MAX , Total impurity 1% MAXApplication: DARUNAVIR INTERMEDIATES