An object of the present invention is to provide a method for manufacturing an optically active menthol having fewer steps, which generates less environmentally polluting waste because a catalytic reaction is involved in all of the steps, and is capable of saving a production cost. The present invention relates to a method for manufacturing an optically active menthol, including the following steps: A-1) asymmetrically hydrogenating at least one of geranial and neral to thereby obtain an optically active citronellal, B-1) conducting a ring-closure reaction of the optically active citronellal in the presence of an acid catalyst to thereby obtain an optically active isopulegol, and C-1) hydrogenating the optically active isopulegol to thereby obtain an optically active menthol.
Evaluation of several fluorinated ATPH derivatives as functionalized Lewis acid receptors for conjugate alkylation to α,β-unsaturated aldehydes with alkyllithium nucleophiles
Several fluorinated aluminumtris(2,6-diphenylphenoxide) (ATPH) derivatives have been synthesized to evaluate, as functionalized Lewis acid receptors, the conjugate alkylation ability to α,β-unsaturated aldehydes by the combined use of alkyllithium nucleophiles. Among these, 3,4,5-F3-ATPH was found to be the most satisfactory.
A catalyst for obtaining isopulegol of high diastereoselectivity by highly selective cyclization reaction of citronellal is provided. The present invention relates to an organoaluminum compound obtained by reacting at least one organoaluminumoxy compound selected from the group consisting of chain aluminoxanes, cyclic aluminoxanes and bis(dialkylaluminumoxy)alkylboranes, with at least one hydroxy compound selected from the group consisting of diarylphenols, bis(diarylphenol) compounds, biaryldiols, dimethanols and silanols.
established that the acidity of phenol can be fine-tuned with substituents on its aromatic ring via through-bond effects, the role of through-space effects on the acidity of phenols is presently poorly understood. Here, we present integrated experimental and computational studies on substituted 2,6-diarylphenols that demonstrate the essential contribution from through-space OH−π interactions and O––π interactions
A process for producing a polyphenylene ether by oxidative polymerization of a phenol compound using a catalyst and an oxygen-containing gas, wherein the catalyst comprises a copper compound, a bromine compound, a diamine compound represented by the following formula (1) :
(wherein, R1, R2, R3 and R4 each independently represents hydrogen or a C1-6 linear or branched alkyl group with the proviso that all of them do not represent hydrogen simultaneously, and R5 represents a linear or methyl-branched C2-5 alkylene group), a tertiary monoamine compound and a secondary monoamine compound, wherein the process comprises the steps of: controlling the absolute pressure at a gaseous phase of a reaction vessel to a range of from 0.098 MPa to less than 0.392 MPa; and feeding the oxygen-containing gas to the reaction vessel, the oxygen-containing gas having an oxygen partial pressure, in terms of an absolute pressure, of from 0.0147 MPa to 0.0883 MPa.