Synthesis of 14C-dilevalol

[1-14C]-Dilevalol 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 α-methyl benzyl protecting group avoided most of the apparent autoradiolysis. (author)