- STEROIDS .LIII. TRANSFORMATION OF 3β-ACETOXY-5α-ANDROSTAN-17-ONE INTO 17α- AND 17β-AMINO DERIVATIVES OF 5α-ANDROSTAN-3β-OL
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The epimeric 17α- and 17β-amino-5α-androstan-3β-ols were synthesized from 3β-acetoxy-5α-androstan-17-one.The configurations at the C17 atom were demonstrated by the 1H NMR method.
- Nadaraia, N. Sh.,Sladkov, V. I.,Kuleshova, L. N.,Suvorov, N. N.
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p. 481 - 485
(2007/10/02)
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- Steroidal N-Nitro-amines. Part 2. Denitroamination of Steroidal 12β-, 17β-, 20β-, and 23R-Nitro-amines
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20β-Nitroaminopregn-5-en-3β-yl acetate (13a), 17β-nitroamino-5α-androstan-3β-yl acetate (14), and 12β-nitroamino-(25R)-5α-spirostan-3β-yl acetate (15a) have been prepared by nitrosation of the corresponding oximes, followed by reduction with sodium borohydride.The 23-nitro-imine (12), obtained by reaction of sarsasapogenin acetate (10) with nitrous acid and boron trifluoride-diethyl ether complex, was similarly reduced to give 23R-nitroamino-(20S,22S,25S)-5β-spirostan-3β-yl acetate (16).Denitroamination of (13a) was achieved by treatment with acetic anhydride and pyridine to give the acetates of pregna-5,20-dien-3β-ol (17), pregn-5-ene-3β,20β-diol (18), 17α-methyl-D-homo-androst-5-ene-3,17aβ-diol (19), and 17α-methyl-12a-methylene-C(12a)-homo-18-norandrost-5-en-3β-ol (20).Under the same conditions the nitro-amine (14) afforded the acetates of 5α-androst-16-en-3β-ol (27a), 17β-methyl-18-nor-5α-androst-12-en-3β-ol (28a), 17-methyl-18-nor-5α-androst-13(17)-en-3β-ol (29a), and 17β-methyl-18-nor-5α-androst-13-en-3β-ol (30a).Denitroamination of (15a) took place through the expected C-nor-D-homo rearrangement producing 14(13->12αH)abeo-(25R)-5α-spirost-13(18)-en-3β-yl acetate (31) in high yield and a minor amount of 14(13->12)abeo-(25R)-5α-spist-12-en-3β-yl acetate (32).The trans-stereochemistry of the β-hydrogen-elimination produced in the denitroamination of (16) was established by using labelled sarsasapogenin (10) biosynthesized by Agave attenuata from mevalonic acid.
- Francisco, Cosme G.,Freire, Raimundo,Hernandez, Rosendo,Melian, Daniel,Salazar, Jose A.,Suarez, Ernesto
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p. 297 - 304
(2007/10/02)
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