152044-54-7Relevant articles and documents
Total synthesis of epothilone B
Valluri, Muralikrishna,Hindupur, Rama M.,Bijoy, Panicker,Labadie, Guillermo,Jung, Jae-Chul,Avery, Mitchell A.
, p. 3607 - 3609 (2001)
Figure presented Epothilone A, 1, R = H Epothilone B, 2, R = Me A convergent and stereoselective total synthesis of epothilone B (2) is described. The key steps are Normant reaction, Wadsworth-Emmons reaction of a methyl ketone 14 with the phosphonate reagent 7, diastereoselective aldol condensation of aldehyde 3 with enolate 4 to form the C6-C7 bond, and macrolactonization.
Easy access to the epothilone family - Synthesis of epothilone B
Mulzer, Johann,Mantoulidis, Andreas,Oehler, Elisabeth
, p. 8633 - 8636 (1998)
An easy access to four out of five naturally occurring epothilones (A- E, 1-5) is reported. Key steps are an enantioselective Mukaiyama type aldol reaction, (E)- and (Z)-selective olefinations, and a sulfone alkylation.
BLUE LIGHT BLOCKLING SYSTEM CONTAINING PYRAZOLINE OR/AND BENZOIC ACID COMPOUNDS
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Paragraph 0029; 0041-0043, (2019/09/17)
The present invention relates to an blue light blocking system characterized in that the blue light blocking agents possess the structure of a pyrazoline of the formula (I) or/and a phenylacrylic acid of the formula (II). The compounds of formula (I) or / and formula (II) fully cover the range of short-wavelength blue light to protect eyes; it can also selectively absorb long-wavelength blue light, so that the transmitted light can provide a particularly good visual experience to humans. The invention is applicable to products such as optical films, optical lenses, goggles, skin care, lighting devices, paints, adhesives, or panels. These products have a light-colored appearance and the penetrating light provides an excellent visual experience for humans.
Total synthesis of epothilones using functionalised allylstannanes for remote stereocontrol
Martin, Nathaniel,Thomas, Eric J.
, p. 7952 - 7964 (2013/06/27)
Two syntheses of the C(7)-C(16)-fragment 41 of epothilone D 2 were developed that were based on tin(iv) bromide mediated reactions of 5,6-difunctionalised hex-2-enylstannanes with aldehydes. In the first synthesis, (5S)-6-tert-butyldimethylsilyloxy-5-hydroxy-2-methylhex-2-enyl(tributyl) stannane 20 was reacted with (E)-but-2-enal to give (2S,7R,4Z,8E)-1-tert- butyldimethylsilyloxy-5-methyldeca-4,8-diene-2,7-diol 26 containing ca. 20% of its (7S)-epimer. Following desilylation, the crystalline (2S,7R)-triol 32 was protected as its acetonide 33 and esterified to give the (4-methoxybenzyloxy) acetate 34. An Ireland-Claisen rearrangement of this ester gave methyl (2R,3S,10S,4E,7Z)-3,7-dimethyl-10,11-(dimethylmethylene)dioxy-2-(4- methoxybenzyloxy)undeca-4,7-dienoate 35 that was converted into (2S,9S,6Z)-2,6-dimethyl-9,10-(dimethylmethylene)dioxydec-6-en-1-ol 41 by regioselective alkene manipulation, ester reduction and cleavage of the resulting terminal diol 40 with a reductive work-up. The second synthesis involved the tin(iv) bromide mediated reaction between the stannane 20 and (3S)-4-(4-methoxybenzyloxy)-3-methylbutanal 44 that gave (2S,7S,9S,4Z)-1-tert- butyldimethylsilyloxy-5,9-dimethyl-10-(4-methoxybenzyloxy)dec-4-ene-2,7-diol 45 containing ca. 20% of its (7R)-epimer. After desilylation and protection of the vicinal diol as its acetonide 46, a Barton-McCombie reductive removal of the remaining hydroxyl group gave the (2S,9S,6Z)-2,6-dimethyl-9,10- (dimethylmethylene)dioxydec-6-en-1-ol 41 after oxidative removal of the PMB-ether. The first of these syntheses uses just one chiral starting material, but the second is shorter and more convergent. It was therefore modified by the use of (5S)-6-tert-butyldimethylsilyloxy-5-(2-trimethylsilylethoxy)methoxy-2- methylhex-2-enyl(tributyl)stannane 49 that reacted with (3S)-4-(4- methoxybenzyloxy)-3-methylbutanal 44 to give a 50:50 mixture of the C(4)-epimers of (2S,9S,6Z)-10-tert-butyldimethylsilyloxy-1-(4-methoxybenzyloxy)-2,6- dimethyl-9-(2-trimethylsilylethoxy)methoxydec-6-en-4-ol 50 with high fidelity for formation of the (Z)-alkene. Following the Barton-McCombie deoxygenation, the product 52 was taken through to (2S,9S,6Z,10E)-2,6,10-trimethyl-11-(2- methyl-1,3-thiazol-4-yl)-9-(2-trimethylsilylethoxy)methoxyundeca-6,10-dienal 59 that corresponded to the fully functionalised C(7)-C(17) fragment of epothilone D 2. A precedented stereoselective aldol condensation followed by O-protection, selective deprotection, oxidation and macrocyclisation then gave the macrolide 71 that was deprotected to complete a synthesis of epothilone D 2. Finally regio- and stereo-selective epoxidation gave epothilone B 1.
FLUORESCENT AGENT HAVING ETHYNYL GROUP
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Page/Page column 6, (2010/12/29)
There are provided novel fluorescent agents, such as pyrazoline compounds represented by formula (I): (wherein R1, R2 and R3 are as defined in the specification), having an ethynyl group in the molecule, which have high absorptivity in the ultraviolet-visible short wavelength range (for example, 350 nm-420 nm).