- Preparation method of gamma-substituted hexadienoic acid
-
The invention relates to a preparation method of gamma-substituted hexadienoic acid. The method is characterized by comprising the following steps: (1) at -10-40 DEG C, adding a solvent, a catalyst and a catalytic assistant into a reaction vessel, stirring, introducing oxygen, adding 1-(2-furyl)-1-alkyl methanol, controlling the molar ratio of the catalyst to the catalytic assistant to the 1-(2-furyl)-1-alkyl methanol at 0.0001-5:0.0001-3:100, reacting at 0-200 DEG C under 0.1-20 MPa for 1-74 h, wherein the solvent is a mixed solution composed of a water phase and an organic phase according toa volume ratio of 1:0.01-3, the water phase is a phosphate acidic solution, the organic phase is a reaction inert solvent, the catalyst is a palladium compound, and the catalytic assistant is an amine or phosphine compound; and (2) cooling the reaction vessel to room temperature, adding an organic solvent, extracting, and carrying out reduced pressure distillation on the organic phase. The methodhas the advantages that the defect of technical economy in an existing synthesis route is overcome, the technological process is simplified, consumption and emission are reduced, energy consumption and cost are reduced, and the method is suitable for industrial production for increasing productivity.
- -
-
Paragraph 0020; 0024
(2021/01/20)
-
- Elucidation of pseurotin biosynthetic pathway points to trans-acting C-methyltransferase: Generation of chemical diversity
-
Pseurotins comprise a family of structurally related Aspergillal natural products having interesting bioactivity. However, little is known about the biosynthetic steps involved in the formation of their complex chemical features. Systematic deletion of the pseurotin biosynthetic genes in A. fumigatus and invivo and invitro characterization of the tailoring enzymes to determine the biosynthetic intermediates, and the gene products responsible for the formation of each intermediate, are described. Thus, the main biosynthetic steps leading to the formation of pseurotinA from the predominant precursor, azaspirene, were elucidated. The study revealed the combinatorial nature of the biosynthesis of the pseurotin family of compounds and the intermediates. Most interestingly, we report the first identification of an epoxidase C-methyltransferase bifunctional fusion protein PsoF which appears to methylate the nascent polyketide backbone carbon atom in trans. A maze: Pseurotins are a family of structurally related bioactive natural products from Aspergilli. Through genetic and biochemical studies, the biosynthetic pathway for the formation of azaspirene, synerazol, and pseurotin A/D have been elucidated, and reveal the combinatorial nature of their biosyntheses. PsoF was identified as bifunctional epoxidase methyltransferase enzyme, thus providing the first example of a trans-acting polyketide C-methyltransferase.
- Tsunematsu, Yuta,Fukutomi, Manami,Saruwatari, Takayoshi,Noguchi, Hiroshi,Hotta, Kinya,Tang, Yi,Watanabe, Kenji
-
p. 8475 - 8479
(2014/08/18)
-
- Benzocyclization of 2,4-Hexadienoic Acids. Synthesis of (R)-(-)-Curcuphenol Acetate
-
A simple and general benzocyclization sequence, useful in the conversion of α-methylene ketones/aldehydes 1a-f to phenolic acetates 6a-g via the dienoic acids 5a-g is presented.The technique has provided a new route to the terpenoids, thymol acetate (6f) and (R)-(-)-curcuphenol acetate (6g).
- Murali, D.,Rao, G. S. Krishna
-
p. 254 - 256
(2007/10/02)
-
- Preparation of Methine Homologues of Aldehydes and Carboxylic Acids
-
Dilithium salts of carboxylic acids add to glyoxal mono(dimethylhydrazone) (5) to give salts of β-hydroxy carboxylic acids.Reaction with tosyl chloride affords via decarboxylation the corresponding unsaturated aldehyde hydrazones 10 or 15, which are easily hydrolyzed and oxidized to form unsaturated carboxylic acids.By this method aldehydes and/or carboxylic acids may be extended by one methine group.Extension by three methine groups can be achieved with vinylogous monohydrazones such as 23.
- Zimmermann, Birgit,Lerche, Holger,Severin, Theodor
-
p. 2848 - 2858
(2007/10/02)
-