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Diketo steroids

Diketo steroids have been prepared by air oxidation of 3-keto-5i5-steroids in potassium /-butoxide-t-butanoF or by hydrolysis of 4,5-epoxy-3-ketones followed by dehydration. However, the most general synthesis is that used by Camerino et al. to prepare Vketo-A-norandrostanes and pregnanes. Hydroxylation of 17a,20.20,21-bismethylenedioxypregn-... [Pg.422]

The reaction of A -3-ketosteroids with 2,6-di-tertbutyI-p-cresol is specific, and different analytes yield various colors. In alkaline media and in the presence of an oxidant (e.g., hydrogen peroxide), A" -3,1 1-diketo steroids (such as cortisone and prednisone, at levels of 5-25 pg) develop yellow-orange colors with this reagent. [Pg.208]

Oxidation of cholestane-2,3-dione with thallium(in) acetate gave the A-nor-p-keto-ester (131) whereas a low yield of the keto-lactones (132) was obtained from 3,4-diketo-steroids.116... [Pg.306]

Figure 52. Conventional mass spectra of 14 (and 14a) keto and diketo steroids [205]. Figure 52. Conventional mass spectra of 14 (and 14a) keto and diketo steroids [205].
Figure 54. H transfer and A, B, C ring eliminations from 14/J diketo steroids [205]. Figure 54. H transfer and A, B, C ring eliminations from 14/J diketo steroids [205].
Hirschmann and co-workers have reported the synthesis of another A-nor analog of cortisone obtained from the benzilic acid rearrangement of a 2,3-diketo-A -steroid. 17a,20 20,21-Bismethylenedioxypregna-L4-diene-... [Pg.424]

A few other oxidations involve no C=C bond cleavage. Cti-9-octadecene gave 9.10-diketo-octadecane with RuO /aq. Na(C10)/( Bu N)Br/CHjCl2 [324], while cyclo-octene was oxidised by RnCyaq. Na(10 )/DCE to 8-oxo-octanal [325]. Oxidation of A -, and A - steroids using RuO /aq. Na(10 )/acetone gave cis-diols, diones and acids [303] while RuO /aq. Na(10 )/CHjCyCH3CN oxidised 2,3-dichlorodecene to decane-2,3-dione [326]. [Pg.19]

Methyl-l,3-cyclohexanedione has been used as starting material for the syntheses of several polycyclic compounds for projected syntheses of steroids and terpenoids.11-13 It has also been used to prepare l -diketo-Sa-methyl-l a-octahydro-naphthalene.3 4- 16... [Pg.94]

Oxidation of steroid enones3-Keto-A4-steroids are oxidized by blue tetrazolium (1) in an alkaline medium to 2,6-diketo-A4-steroids in 70-80% yield. Other examples ... [Pg.43]

Use for transcyanohydrinatiow. preparation in high yield of the 17-monocyanohydrin of a 3,17-diketo-A -steroid by hydrogen cyanide exchange with the reagent. ... [Pg.736]

Diketo-10(5 4)-abeo-steroids from 3-keto-4,5-oxidosteroids... [Pg.611]

See other pages where Diketo steroids is mentioned: [Pg.419]    [Pg.422]    [Pg.453]    [Pg.453]    [Pg.453]    [Pg.219]    [Pg.457]    [Pg.118]    [Pg.223]    [Pg.924]    [Pg.11]    [Pg.336]    [Pg.848]    [Pg.419]    [Pg.422]    [Pg.453]    [Pg.453]    [Pg.453]    [Pg.219]    [Pg.457]    [Pg.118]    [Pg.223]    [Pg.924]    [Pg.11]    [Pg.336]    [Pg.848]    [Pg.101]    [Pg.245]    [Pg.26]    [Pg.394]    [Pg.101]    [Pg.335]    [Pg.339]    [Pg.101]    [Pg.1372]    [Pg.11]    [Pg.502]    [Pg.191]    [Pg.316]    [Pg.67]    [Pg.146]    [Pg.246]   
See also in sourсe #XX -- [ Pg.212 ]



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