26048-46-4Relevant articles and documents
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Sax,Bernstein
, p. 1069,1077 (1951)
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The mechanisms of the rearrangements of allylic hydroperoxides: 5α-hydroperoxy-3β-hydroxycholest-6-ene and 7α-hydroperoxy- 3β-hydroxycholest-5-ene
Beckwith, Athelstan L. J.,Davies, Alwyn G.,Davison, Ian G. E.,Maccoll, Allan,Mruzek, Margaret H.
, p. 815 - 824 (2007/10/02)
The rearrangement of 5α-hydroperoxy-3β-hydroxycholest-6-ene in solution under 18O2, gives isotopically normal 7α-hydroperoxy-3β-hydroxycholest-5-ene, whereas the epimerization of this product to give 7β-hydroperoxy-3β-hydroxycholest-5-ene involves incorporation of 73-83% of 18O2 into the hydroperoxy group. These two reactions proceed through the corresponding hydroperoxyl radicals, which have different e.s.r. spectra and which therefore must exist as separate and distinct species. The former reaction shows a first-order dependence on hydroperoxide concentration, and a half-order dependence on t-butyl hyponitrite which was added as an initiator. It is suggested that the first reaction involves a sigmatropic [2,3]-rearrangement, whereas the second reaction proceeds through a dissociative mechanism.
SYNTHESIS OF PERFLUOROALKYL STEROIDS AS CO-EMULSIFYING AGENTS FOR 1-BROMOPERFLUOROOCTANE AND OTHER PERFLUOROCOMPOUNDS
Sharts, C. M.,Malik, A. A.,Easdon, J. C.,Khawli, L. A.,Long, D. M.,et. al.
, p. 365 - 384 (2007/10/02)
Syntheses of steroids substituted with perfluoroalkyl groups at C-3, C-7, and C-20 positions on the steroid nucleus are described.Synthetic methods employed included coupling of perfluoroalkylcopper with allylic bromides and Grignard reactions.Free radical additions of perfluoroalkyl iodide to unsaturated steroids and reaction of perfluoroalkyl Grignard reagents with 6-ketosteroid were unsuccessful.Perfluoroalkyl-substituted steroids are desired for testing as co-emulsifying agents in perfluorooctyl bromide/water emulsions which are used as blood substitutes (synthetic blood).A rationale for the choice of perfluorooctyl bromide as the oxygen-carrying agent in the fluorocarbon-based blood substitute and on the use of perfluoroalkyl-substituted steroids as co-emulsifying agents is also reported.
