- Oxymetallation. Part 24. Preparation of cyclic peroxides by cycloperoxymercuriation of unsaturated hydroperoxides
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Seventeen unsaturated hydroperoxides have been converted by treatment with mercury(II) acetate and/or mercury(II) nitrate into nineteen new mercuriated cyclic peroxides and by subsequent demercuriation with alkaline sodium borohydride, six new mercury-free peroxides have been isolated. The results greatly extend the range of such reactions and provide information about the stereoselectivities and relative ease of several different modes of cycloperoxymercuriation. It is suggested that the reactions with mercury(II) acetate are kinetically controlled whereas those with mercury(II) nitrate show a component of thermodynamic control of product distribution.
- Bloodworth,Curtis,Spencer,Tallant
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p. 2729 - 2750
(2007/10/02)
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- Oxymetallation. Part 12. Further Syntheses of Monocyclic Peroxides via Peroxymercuriation
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The scope of cycloperoxymercuriation as a route to monocyclic peroxides has been investigated by studying the reaction of mercury(II) nitrate with ten representative dienes plus hydrogen peroxide, and with two alkenyl hydroperoxides.By hydrogeno- and bromo-demercuriation of the resultant products, seven new methyl- and bromomethyl-substituted 1,2-dioxacyclo-pentanes and -hexanes have been prepared.The geometrical isomers of three of the 1,2-dioxacyclopentanes (4), (8), and (9) have been separated and assigned cis and trans configurations, and each of the four diastereoisomers of 4-bromo-3-bromomethyl-5-methyl-1,2-dioxacyclopentane (11) has been isolated.Two diastereoisomers of 4-bromo-6-bromomethyl-3-methyl-1,2-dioxacyclohexane (13) are formed and have been separated; their 1H n.m.r. spectra indicate that each has a chair conformation with equatorial methyl and bromomethyl groups, the stereoisomerism arising from the disposition of the bromine substituent.The by-products of peroxymercuriation-reduction have been shown to be unsaturated alcohols whose formation is strongly favoured where the cycloperoxymercurial contains an endocyclic mercurio-substituent.
- Bloodworth, A. J.,Khan, Jamil A.
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p. 2450 - 2457
(2007/10/02)
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