PYRANOQUINAZOLINE DERIVATIVES AND NAPHTHOPYRAN DERIVATIVES
[Problem] A problem is presented in that conventional photochromic compounds cannot be considered adequate in terms of the colorizing/decolorizing rate and durability, and the production process therefore has many steps. The present invention provides an industrially applicable photochromic compound that has both a rapid colorizing/decolorizing reaction and high durability and can also be synthesized at a low cost. [Solution] This compound is characterized in that etheric oxygen atoms are bonded to the carbon atoms at position 1 of a pyranoquinazoline (8H-pyrano[3,2-f]quinazoline) skeleton and position 10 of a naphthopyran (3H-naphtho[2,1-b]pyran) skeleton, said compound having photochromic properties and being a photochromic compound that has both a rapid colorizing/decolorizing reaction and high durability. Also provided is an industrially applicable photochromic compound that can be synthesized at a low cost.
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Paragraph 0196-0197
(2020/05/14)
Development of a one-pot method for the homologation of aldehydes to carboxylic acids
A highly efficient method is described for the one-carbon homologation of aldehydes to carboxylic acid derivatives employing the reaction of a 1,1-bis-dimethylphosphonate derivative with the aldehyde and controlled acid hydrolysis of the derived α-phosphonoenamine intermediate.
McNulty, James,Das, Priyabrata
experimental part
p. 7794 - 7800
(2009/12/26)
An improved and versatile method for the rapid synthesis of aryldihydrobenzofuran systems by a boron tribromide-mediated cyclization reaction
Boron tribromide is presented as a highly reactive reagent that simultaneously allows the demethylation and fully diastereoselective cyclization of different precursor molecules, obtained by an aldol-type reaction, to a series of hydroxylated aryldihydrobenzofuran systems in racemic form. The latter are often found as key structures in natural compounds of different classes. Syntheses of educts, which mainly took advantage of a versatile Rieche formylation, are also described.
Detterbeck, Richard,Hesse, Manfred
p. 343 - 360
(2007/10/03)
Synthesis of the Bacterial Coenzyme Methoxatin
The details of a total synthesis of methoxatin (1), the coenzyme of several bacterial alcohol dehydrogenases, are presented.Methoxatin has been prepared in 13 steps by starting from 2,3-dimethoxytoluene.The successful synthetic strategy for construction of the coenzyme used a Pfitzinger synthesis for preparation of the quinoline dicarboxylic acid portion of 1 and an "umpolung" variation of the Reissert indole synthesis for annulation of the remaining pyrrole ring.
Gainor, James A.,Weinreb, Steven M.
p. 2833 - 2837
(2007/10/02)
A convenient entry into the rhoeadan skeleton. Total synthesis of (±)-cis-alpinigenine