- Efficient electrochemical deprotection of carboxylic and amino acids from their 2-(hydroxymethyl)-1,3-dithiane (dim) esters
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formula presented Carboxylic acids and amino acids are electrochemically deprotected from their 2-(hydroxymethyl)-1,3-dithiane (Dim) esters.
- Barnhurst, Loren A.,Wan, Yongqin,Kutateladze, Andrei G.
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- POTASSIUM CHANNEL MODULATORS
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Disclosed herein are KCNQ potassium channels modulators of formula (I) wherein ring G1, X, R1, and R2 are as defined in the specification. Compositions comprising such compounds; and methods for treating conditions and disorders using such compounds and compositions are also described
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Page/Page column 60
(2010/12/26)
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- Addition of carboxyalkyl radicals to alkenes through a catalytic process, using a Mn(II)/Co(II)/O2 redox system
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A novel strategy for production of mono- and dicarboxylic acids by the addition of carboxyalkyl radicals to alkenes and dienes, respectively, was successfully developed through a catalytic process with use of Mn(II)/Co(II)/O2 system. Thus, a variety of carboxylic acids were prepared by the reaction of alkenes and dienes with acid anhydrides in the presence of a very small amount of Mn(OAc)2 (0.5 mol %) and Co(OAc)2 (0.1 mol %) under dilute dioxygen.
- Hirase, Koji,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 5974 - 5976
(2007/10/03)
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- DERMATOLOGICAL COMPOSITIONS AND METHODS
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Disclosed are methods and compositions for regulating the melanin content of mammalian melanocytes; regulating pigmentation in mammalian skin, hair, wool or fur; treating or preventing various skin and proliferative disorders; by administration of various compounds, including alcohols, diols and/or triols and their analogues.
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- Highly stereoselective tandem cyclizations of 5-hexenyllithiums: Preparation of endo-2-substituted bicyclo[2.2.1]heptanes and 3-substituted trans-bicyclo[ 3.3.0] octanes
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Tandem cyclization of diolefinic alkyllithiums, derived from acyclic diolefinic alkyl iodides by low-temperature lithium-iodine exchange, proceeds via two highly stereoselective and totally regiospecific 5-exo-trig ring closures to deliver bicyclic alkyllithiums. Trapping of the organolithium product by addition of an electrophile cleanly affords functionalized bicyclic molecules in good yield. In this way both endo-2-substituted bicyclo[2.2.1]heptanes and 3-substituted trans-bicyclo[3.3.0]octanes have been prepared in isolated yields of 65-80% from the readily available 3-(2-iodoethyl)-1,5-hexadiene (5) and 7-iodo-4-ethenyl-1-heptene (9), respectively. Attempts to effect tandem cyclization of 5,10-undecadienyllithium (11), which would be mediated by a secondary alkyllithium species, were unsuccessful. The results suggest that tandem anionic cyclization provides a convenient route to a variety of bicyclic systems not readily available by other approaches.
- Bailey, William F.,Khanolkar, Atmaram D.,Gavaskar, Kaustubh V.
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p. 8053 - 8060
(2007/10/02)
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- Manganese(III)-Mediated γ-Lactone Annulation
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The annulation of a γ-lactone ring onto an alkene by manganese(III) acetate oxidation of acetic acid was investigated.The regioselectivity of addition to unsymmetrically substituted alkenes is reported along with the stereoselectivity of addition to various acyclic and cyclic alkenes.Alkenes with ionization potentials above 8.2 eV were found to react in good yield.The role of acetic anhydride in these reactions was studied, and it was shown to be oxidized faster than acetic acid and also led to different products.The fate of oxidized acetic acid or anhydridein the absence of suitable acceptor molecule has also been quantitatively identified.The relationship of enolizability, or C-H acidity, of the carboxylic acid being oxidized was established quantitatively.
- Fristad, William E.,Peterson, John R.
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