Protection of the allylic alcohol double bond from catalytic reduction in the preparation of [1-3H]morphine and [1-3H]codeine

The t-butyldimethylsilylation of the allylic alcohol of 1-iodomorphine and 1-iodocodeine protects the double bond of these molecules from catalytic reduction while allowing the reduction of the aryl iodide. This selectivity has been applied to the preparation of tritiated morphine and codeine without complicating over reduction to the dihydromorphine and dihydrocodeine. © 1998 John Wiley & Sons, Ltd.