- A Baker-Venkataraman retro-Claisen cascade delivers a novel alkyl migration process for the synthesis of amides
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A simple extension of the carbamoyl Baker-Venkataraman rearrangement has been developed. If residual water in the reaction is not strictly excluded a Baker-Venkataraman retro-Claisen cascade takes place, giving amide products, in which an alkyl group apparently migrates between two functionalities of the substrate.
- Ameen, Dana,Snape, Timothy J.
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supporting information
p. 1816 - 1819
(2015/03/30)
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- Intramolecular ketone-olefin radical cyclization with low-valent titanium reagent: Synthesis of benzopyrans
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A novel protocol for intramolecular ketyl-olefin radical cyclization with low-valent titanium reagent is outlined. It allows the formation of the benzopyran nucleus from ortho-allyloxy propiophenones as the sole product in moderate yields via intramolecular radical cyclization. Copyright Taylor & Francis Group, LLC.
- Nayak, Sandip K.,Bhatt, Suchitra,Roy, Kshama
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scheme or table
p. 2969 - 2975
(2010/11/05)
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- Synthesis of the potassium channel opener (3S,4R)-3,4-dihydro-4-(2,3- dihydro-2-methyl-3-oxo-pyridazin-6-yl)oxy-3-hydroxy-6-(3-hydroxyphenyl) sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran
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The preparation of the potassium channel opener (3S,4R)-3,4-dihydro-4-(2,3- dihydro-2-methyl-3-oxo-pyridazin-6-yl)oxy-3-hydroxy-6-(3-hydroxyphenyl) sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran (1) as a single enantiomer is reported. Considerable improvement
- Magano, Javier,Acciacca, Allison,Beylin, Vladimir,Spence, Julie,Dunn, Peter,Hughes, Mike
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p. 3569 - 3578
(2008/03/14)
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- Benzopyrans
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A compound of the formula: STR1 or a pharmaceutically acceptable salt thereof, wherein X is O, S or NH; R and R1 are each independently selected from H and C1 -C4 alkyl or taken together represent C2 -C6 alkylene; R2 is H or C1 -C4 alkyl; R3 is a 6-membered heterocyclic ring containing 2N hetero-atoms, said ring being linked to X by a ring carbon atom, optionally benzo-fused and optionally substituted, including in the benzo-fused portion, by C1 -C6 alkyl, hydroxy, --OR5, halo, --S(O)m R5, oxo, amino, --NHR5, --N(R5)2, cyano, --CO2 R5, --CONH2, --CONHR5 or --CON(R5)2, with the proviso that R3 is not an N--(C1 -C6 alkyl)pyridonyl group; R4 is phenyl substituted by a hydroxy group and optionally further substituted by 1 or 2 substitutents each independently selected from hydroxy, C1 -C6 alkyl, --OR5, halo, cyano and nitro; R5 is C1 -C6 alkyl; R6 is --OR5, --NHR5, --N(R5)2, --SR5 or --NHR9 ; R7 is cyano; R8 is --OR5, --NHR5, --N(R5)2, or --NHR9 ; R9 is phenyl optionally substituted by C1 -C6 alkyl, hydroxy, --OR5, halo, cyano or nitro; and m is 0, 1 or 2.
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- BENZOPYRANES AS POTASSIUM CHANNEL OPENERS
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The present invention relates to compounds of formula (I) and the pharmaceutically acceptable salts thereof, wherein the dashed line represents an optional covalent bond; X is O, NH, S or a direct link; R. sup.3 is hydroxy when the dashed line does not represent a covalent bond and R 3 is absent when the dashed line represents a covalent bond; R. sup.4 is (a), when X is O, a group of formula (i), (b), when X is O, NH or S, optionally substituted hydroxyphenyl, (c) an optionally substituted 4-to 7-membered heterocyclic ring, or (d), when X is NH, a group of formula (ii). The compounds are useful for the treatment of disease associated with the altered tone or motility of smooth muscle. STR1
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