Synthesis of 14C-dilevalol

[1‐14C]‐Dilevalol, (Figure 1), was synthesized from [1‐14C]‐acetyl chloride. A key step in the synthesis, the coupling of a protected chiral amine with a bromoketone, was very sensitive to the choice of protecting group. The authors attribute this sensitivity to unexpected and severe radiolytic decomposition of the reaction product. The use of a simple benzyl. protecting group rather than an α‐methyl benzyl protecting group avoided most of the apparent autoradiolysis.