Synthesis of [19-2H3]progesterone and [18-2H3]progesterone

[19-2H3]Progesterone has been prepared from 3,3 : 20,20-bisethylenedioxy[19-2H3]pregn-5-en-19-ol by reduction of the derived 19-toluene-p-sulphonate with lithium triethylborodeuteride (‘superdeuteride’) followed by hydrolysis of the ethylenedioxy groups. [18-2H3] Progesterone was obtained from (20R)-3β-acetoxy-pregn-5-eno-20,18-lactone via conversion into methyl (20R)-3β-20-dihydroxypregn-5-en-18-oate: a two-stage introduction of three atoms of deuterium at C-18 via the toluene-p-sulphonate of the derived [18-2H2]-18-ol required unusual experimental conditions.