Synthesis of adenosine 5′[(R)α- ¹⁷ O]triphosphate

Adenosine 5′[(S)α-thio]triphosphate is converted predominatly into adenosine 5′[γ-18O]triphosphate by bromine in [18O]water, but adenosine 5′[(S)α-thio]diphosphate gives adenosine 5′[(R)α-17O]diphosphate on treatment with bromine in [17O]water which can be converted enymically into adenosine 5′[(R)α-17O]-triphosphate.