2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 19-Hydroxy-1,4-androstadien-3-one

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Reaction Steps

The 1,4 and 6-methylated derivatives for the 4-androstene-3, 19-diones of the present invention are best prepared by introducing the desired methyl group into the 19-hydroxy-androstene and oxidizing the 19-alcohol to the aldehyde. The 1α-methyl-19-hydroxy-4-androsten-3-ones which can be oxidized to the aldehydes are prepared in two steps. The reaction of dichlorodicyanobenzoquinone with a 19-hydroxy-4-androsten-3-one in refluxing dioxane or methylenechloride for 24-72 hours to produce the corresponding 19-hydroxy-1,4-androstadien-3-one. However, two restrictions in this sequence are necessary. First, the 19-hydroxy group must be protected as an ester or an ether in order to avoid aromatization. Secondly, the 1-position must possess an axial hydrogen atom suitable for elimination. Thus, the 1α-methyl androstene is not reactive although the 1β-methyl androstane is. Following this procedure 17β,19-dihydroxy-7α-methyl-4-androsten-3-one dipropionate is converted to 17β,19-dihydroxy-7α-methyl-1,4-androstadien-3-one dipropionate. Similarly, 19-hydroxy-6α-methyl-4-androstene-3,17-dione acetate forms 19-hydroxy-6α-methyl-1,4-androstadiene-3,17-dione acetate and 1β-methyl-19-tetrahydropyranyloxy-4-androstene-3,17-dione forms 1-methyl-19-tetrahydropyranyloxy-1,4-androstadiene-3,17-dione.

Provenance & Evidence