- A practical synthesis of long-chain iso-fatty acids (iso-C 12-C19) and related natural products
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A gram-scale synthesis of terminally-branched iso-fatty acids (iso-C 12-C19) was developed commencing with methyl undec-10-enoate (methyl undecylenate) (for iso-C12-C14) or the C15 and C16 lactones pentadecanolide (for iso-C 15-C17) and hexadecanolide (for iso-C18-C 19). Central to the approaches outlined is the two-step construction of the terminal isopropyl group through addition of methylmagnesium bromide to the ester/lactones and selective reduction of the resulting tertiary alcohols. Thus, the C12, C17 and C18 iso-fatty acids were obtained in three steps from commercially-available starting materials, and the remaining C13-C16 and C19 iso-fatty acids were prepared by homologation or recursive dehomologations of these fatty acids or through intercepting appropriate intermediates. Highlighting the synthetic potential of the iso-fatty acids and various intermediates prepared herein, we describe the synthesis of the natural products (S)-2,15-dimethylpalmitic acid, (S)-2-hydroxy-15-methylpalmitic acid, and 2-oxo-14-methylpentadecane.
- Richardson, Mark B.,Williams, Spencer J.
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supporting information
p. 1807 - 1812
(2013/10/22)
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- METHOD FOR PRODUCING CROSS-COUPLING COMPOUND
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To provide a method for performing a cross-coupling reaction of a Grignard compound with an alkyl halide simply, efficiently and in high yield, a method for obtaining a ω-bromo long chain carboxylic acid simply and efficiently using an easily obtainable raw material and a method for producing a useful branched fatty acid simply and efficiently. [R1: an alkyl group having 1 to 15 carbon atoms, R2: an alkyl group having 1 to 30 carbon atoms with a carboxyl group and X and X': a halogen atom] [n : an integer of 9 to 17] [n : an integer of 9 to 17, R1a : a branched alkyl group having 3 to 8 carbon atoms and X: a halogen atom]
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Page/Page column 19; 21
(2010/01/29)
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