- Organocatalytic Asymmetric Formal [4 + 2] Cycloaddition of in Situ Oxidation-Generated ortho-Quinone Methides and Aldehydes
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An unprecedented chiral secondary amine-catalyzed formal [4 + 2] annulation of aldehydes and oxidation-generated β-unsubstituted o-QMs is reported. This asymmetric protocol allows direct functionalization of the benzylic C-H bonds and furnishes [4 + 2] cycloadducts, chromanols, with excellent enantioselectivity and in up to 92% yield. The usability of this approach was further demonstrated by the enantioselective synthesis of anticancer Rhinacanthins derivative NKPLS8.
- Zhou, Ding,Yu, Xueting,Zhang, Jian,Wang, Wei,Xie, Hexin
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supporting information
p. 174 - 177
(2018/01/17)
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- METHOD OF MAKING VITAMIN K1
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This invention discloses a method of making vitamin K1. The mentioned method of making vitamin K1 comprises performing a first one-pot synthesis with base catalyst, performing a first hydrolysis, performing a substitution, and performing a second one-pot synthesis without metal oxidant. The starting material of this invention is stable 2-methyl-1,4-naphthoquinone. Preferably, this invention provides a method of making vitamin K1 efficiently on simplifying the operation and decreasing the side-product. More preferably, without metal residue, the vitamin K1 of this invention is without metal residue and more safety for clinical application.
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Paragraph 0036-0041
(2016/12/12)
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- A METHOD OF MAKING VITAMIN K1
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This invention discloses a method of making vitamin K1. The mentioned method of making vitamin K1 comprises performing a first one-pot synthesis with base catalyst, performing a first hydrolysis, performing a substitution, and performing a second one-pot synthesis for oxidation reaction without using metal oxidant. The starting material of this invention is stable 2-methyl-1,4-naphthoquinone. Preferably, this invention provides a method of making vitamin K1 efficiently on simplifying the operation and decreasing the formation of side-product. More preferably, without the usage of metal residue in this invention results that the vitamin K1 is more safety for clinical application.
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Paragraph 0049-0051
(2017/03/28)
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- One-pot hydroacetylation of menadione (vitamin K3) to menadiol diacetate (vitamin K4) by heterogeneous catalysis
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Vitamin K4 (menadiol diacetate, MDD) can be easily synthesized through cleaner and more efficient catalytic alternatives following the green chemistry principles. Ionic gold-based hydroxylated fluorides are active bi-functional catalysts for the one-pot hydroacetylation of menadione leading to MDD with 77% selectivity. Unprecedent results were obtained in the presence of oxide-fluoride catalysts by using a microwave-assisted hydrogen-transfer (Meerwein-Ponndorf-Verley reaction) coupled with an acetylation approach, yielding very high selectivities for the target product (95%). Copyright
- Dobrinescu, Claudiu,Iorgulescu, Elena E.,Mihailciuc, Constantin,MacOvei, Dan,Wuttke, Stefan,Kemnitz, Erhard,Parvulescu, Vasile I.,Coman, Simona M.
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experimental part
p. 1301 - 1306
(2012/06/15)
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- The regioselective synthesis of monomethoxynaphthylene diacetates
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Methods for the conversion of 1,4,5-naphthalenetriols into the corresponding monomethoxy diacetates are described. All utilise the formation of peri-bridged intermediates.
- Maiti, Bhim C.,Musgrave, Oliver C.,Skoyles, Douglas
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p. 1765 - 1771
(2007/10/03)
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- Regioselective hydrolysis of diacetoxynaphthalenes catalyzed by Pseudomonas sp. lipase in an organic solvent
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Depending on the relative positions of the acetyl groups in the aromatic rings, the Pseudomonas sp. lipase-catalyzed hydrolysis of diacetoxynaphthalenes in tert-butylmethyl ether proceeds regioselectively to afford the corresponding monoacetates.
- Ciuffreda, Pierangela,Casati, Silvana,Santaniello, Enzo
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p. 317 - 321
(2007/10/03)
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- Molecular and crystal structure of 1,4-diacetoxynaphthalene: Structural analysis of methyl substituted 1,4-diacetoxynaphthalenes
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Methyl substituted 1,4-diacetoxynaphthalenes have been synthesized and analyzed by means of ultraviolet and 1H-nmr.Positional effects of the methyl substitution on the spectroscopic parameters have been rationalized. 6,7-Dimethyl-1,4-diacetoxynaphthalene, V, has been analyzed by X-ray diffraction techniques.Crystals are monoclinic P21, a = 8.816(1), b = 26.676(7), c = 6.189(1) Angstroem, β = 103.9(2) deg and four molecules in the unit cell.
- Rodriguez, Jose Gonzalo,Pablo, Alfonso de,Lerma, Julian Lopez de,Perales, Aurea
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p. 307 - 316
(2007/10/02)
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- Oxidation of 1-Naphthols by Lead Tetraacetate in Acetic Acid
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A detailed study of the lead tetraacetate-acetic acid oxidation of 1-naphthol, 4-acetoxy-1-naphthol, 2-methyl-1-naphthol, 2,3-dimethyl-1-naphthol and 1,2,3,4-tetrahydro-9-anthrol (17) has been carried out.In the case of 1-naphthol the major product was 4-acetoxy-1-naphthol (4), with 2,2-diacetoxynaphthalen-1(2H)-one (2) being the only other product formed in significant yield.Attack at C4 was again the main reaction with 4-acetoxy-1-naphthol, which gave 1,4-naphthoquinone as the major product.Acetoxylation occurred predominantly at C2 with 2-methyl-1-naphthol and 2,3-dimethyl-1-naphthol to give the naphthalen-1(2H)-ones (11) and (12) respectively.In both cases minor amounts of 4-acetoxylated derivatives and quinones were also produced. 1,2,3,4-Tetrahydro-9-anthrol (17) gave an analogous set of products, the yields of which showed as unusual concentration dependence.In dilute solution 10-acetoxy-1,2,3,4-tetrahydro-9-anthrol (19) was produced in high yield, whereas with a high substrate concentration a good yield of 9a-acetoxy-1,2,3,4-tetrahydroanthracen-9(9aH)-one (18) was obtained.
- Greenland, Harry,Pinhey, John T.,Sternhell, Sever
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p. 2067 - 2074
(2007/10/02)
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