- The Synthesis of Long-chain Unbranched Aliphatic Compounds by Molecular Doubling
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A convenient general synthesis, applicable to alkanes and terminally mono- and di-substituted alkanes of any chain length, is described; cyclododecanone is used as the starting material, and the C12 chain is doubled in length as often as required and adjusted first to a multiple of 12, and then to any desired length.
- Paynter, Oliver I.,Simmonds, Derek J.,Whiting, Mark C.
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- A versatile process for the syntheses of very long chain alkanes, functionalised derivatives and some branched chain hydrocarbons
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An earlier method for synthesising very long straight-chain alkanes of very specific lengths has been improved to give, in some cases, gram amounts of materials. Eleven compounds have been made: C98H198, C122H246, C162H326, C194H390, C198H398, C210H422, C242H486, C246H494, C258H518, C294H590 and C390H782. The self-condensation reaction of one of the intermediate aldehydes enabled two chain-branched hydrocarbons to be obtained: C96H193CHRC94H189 where R = CH3 and CH3(CH2)3. Three long-chain compounds containing carboxylic acid groups have been prepared: CH3(CH2)190CO2H, HO2C(CH2)48CO2H and HO2C(CH2)192CO2H. Copyright 1996 by the Royal Society of Chemistry.
- Brooke, Gerald M.,Burnett, Simon,Mohammed, Shahid,Proctor, David,Whiting, Mark C.
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p. 1635 - 1645
(2007/10/03)
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- Studies on the Synthesis of Linear Aliphatic Compounds. Part. 3. The Synthesis of Paraffins with Very Long Chains
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The approach derived in Part 2 has been modified to increase the purity and yield of intermediates.The C12 starting materials have been doubled in chain length five times, and by using components of similar or different chain length in Wittig condensations ω-halogeno-acetals with 12n carbon atoms have been made up with n up to 32.They have been converted into paraffins with 102, 104, 150, 198, 246, 294, and 390 carbon atoms.Those paraffins with 150 or more carbon atoms show chain-folding in the crystalline state; this observation is contributing to the understanding of chain-folding behaviour long known in linear polyethylene but hitherto unknown in essentially pure paraffins.
- Bidd, Ilesh,Holdup, David W.,Whiting, Mark C.
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p. 2455 - 2464
(2007/10/02)
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- Studies on Synthesis of Linear Aliphatic Compounds. Part 2. The Realisation of a Strategy for Repeated Molecular Doubling.
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Routes from C11 and C12 starting-materials, obtainable free from near homologues, to compounds of doubled chain length have been explored as approaches to the synthesis of n-paraffins and of terminally mono- or bi-functional derivatives.Acetylene alkylation routes lead to problems with prtotecting groups, but the use of the Wittig reaction provides a method of molecular doubling convenient for repeated use, with formation of chain-lengths rising in a geometrical progression.The general problems inherent in the synthesis of very long-chain paraffins are discussed, earlier work is reviewed, and criteria for success are suggested.A useful protecting group for hydroxyl, the tri-p-tolylmethyl(trimtyl) ether, is described.
- Igner, Eva,Paynter, Oliver I.,Simmonds, Derek J.,Whiting, Mark C.
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p. 2447 - 2454
(2007/10/02)
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