PREPARATION AND STABILITY OF DL-ALPHA-TOCOPHEROL LABELLED WITH TRITIUM AT HIGH SPECIFIC ACTIVITY

Hydrogen‐tritium exchange labelling methods proved to be unsatisfactory for the preparation of tritiated DL‐α‐tocopherol at high specific activity. The preparation of α‐tocopherol specifically labelled in the 5‐methyl hydrogen positions is described : the method permits specific activities in the curies per millimole range to be readily achieved. The synthesis is also suitable for preparing tocopherol doubly labelled with tritium and carbon‐14. The stability of the tritiated vitamin on storage is discussed. Copyright © 1969 John Wiley & Sons, Ltd.