- Copper-catalysed intramolecular O-H addition to unactivated alkenes
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Intramolecular cyclisation of ω-alkenoic acids and alkenols can be achieved using a catalytic amount of Cu(OTf)2 to afford lactones and cyclic ethers, offering a practical alternative to existing catalysts.
- Adrio, Luis A.,Quek, Louisa Shuyi,Taylor, Jason G.,Kuok (Mimi) Hii, King
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experimental part
p. 10334 - 10338
(2010/02/28)
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- Triflic acid mediated dealkylative lactonisation via NMR-observable alkyloxonium intermediates
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Trifluoromethanesulfonic acid (TfOH) efficiently induces the dealkylative cyclisation of pent-4-enoates to generate γ-lac-tones with high selectivity. For primary alkyl esters bearing an additional alkene, only monolactonisation occurs, even in the presen
- Munoz, M. Paz,Lloyd-Jones, Guy C.
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experimental part
p. 516 - 524
(2009/07/19)
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- Phosphinite ligand effects in palladium(II)-catalysed cycloisomerisation of 1,6-dienes: Bicyclo[3.2.0]heptanyl diphosphinite (B[3.2.0]DPO) ligands exhibit flexible bite angles, an effect derived from conformational changes (exo- or endo-envelope) in the b
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Changes in bidentate ligand structure significantly affect catalytic activity in mono-cationic Pd(II)-catalysed 1,6-diene cycloisomerisation processes to give cyclopentene products. A bicyclo-[3.2.0]heptanyl diphosphinite ligand (B[3.2.0]DPO, 3) is the fi
- Fairlamb, Ian J. S.,Grant, Stephanie,Tommasi, Simona,Lynam, Jason M.,Bandini, Marco,Hao, Dong,Zhenyang, Lin,Whitwood, Adrian C.
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p. 2515 - 2530
(2007/10/03)
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- SIMPLE SYNTHESIS OF γ-LACTONES FROM OLEFINIC NITRILES
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The reaction of substituted 4-pentenonitriles with 50 percent sulphuric acid at 100 deg C afforded γ-lactones in moderate to good yield.
- Tiecco, Marcello,Tingoli, Marco,Testaferri, Lorenzo,Bartoli, Donatella
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p. 2817 - 2824
(2007/10/02)
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- Synthesis of 4-Penten-4-olides (γ-Methylene-γ-butyrolactones) via 4-Pentenoic Acids
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4-Penten-4-olides (γ-Methylene-γ-butyrolactones) 7 are easily accessible starting from allylic alcohols 1, which on ortho ester Claisen rearrangement and hydrolytic work-up furnish 4-pentenoic acids 5.The latter on iodolactonization and hydrogen iodide elimination by means of 1,8-diazabicycloundec-7-ene (DBU) furnish 7, in good over-all yield and with variable substitution patterns. - Iodolactonization under kinetic control shows moderate 1,2- or 1,3-asymmetric induction (3:1 and ca. 2:1, respectively).The composition of the iodolactone mixtures 6 as well as the individual relative configurations are deduced from 1H and 13C NMR data. - Similary, the spirobipentenolide 13 is obtained starting from diethyl diallylmalonate (9) via 11 resulting from ester iodocyclization.
- Guenther, Hans Juergen,Guntrum, Eberhard,Jaeger, Volker
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- Study of urinary excretion compounds of proxibarbal in rat and man
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Potential metabolites of proxibarbal are synthetized and their chemical behaviour is studied. Thin layer chromatography, nuclear magnetic resonance and marked compounds are used to identify urinary excretion compounds in rats and man after absorption of the barbiturate and to point out an original way of metabolism.
- Lambrey,Lafont,Jacquot
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p. 463 - 468
(2007/10/02)
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