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Taxol Nicolaou

Taxol. Nicolaou has reported the use of a pinacol cyclization to close the B ring of taxol, a diterpene of great interest due to its anticancer activity (Eq. 3.12) [30], The reaction proceeded in modest yield (23%), with two of the major side products being a lactol and an olefin. [Pg.74]

Nicolaou, K.C., Liu, J.J., Yang, Z. et al. (1995) Total Synthesis of Taxol. 2. Construction of A and C Ring Intermediates and Initial Attempts to Construct the ABC Ring System. Journal of the American Chemical Society, 117, 634-644. [Pg.195]

Taxol (K. C. Nicolaou) a potent cancer chemotherapy agent. [Pg.496]

Finally, two total syntheses of taxol, accomplished independently at the beginning of the year 1994 by Nicolaou and Holton, and their associates, will be discussed in detail as an example of a natural product, the disponibility in substantial amounts of which is of paramount importance for fighting against some types of cancer. [Pg.338]

The semisynthesis of taxol [1], as well as the synthesis of taxoid model systems have been the focus of extensive research efforts in many laboratories, all over the world, which have greatly simplified the total synthesis of taxol itself. An excellent review by Nicolaou et al. has recently been published in Angewandte Chemie [2]. [Pg.391]

The strategy followed by Nicolaou and his group for the total synthesis of taxol was based on a retrosynthetic analysis already devised by the author in 1992 [6], which implies a convergent synthesis (Scheme 13.6.1). [Pg.393]

The synthesis of this starting material 73 X = SMe also uses interesting strategy. The first step was a Diels-Alder reaction between a cyelopentadiene 77 and the dienophile 62 used by Nicolaou in his taxol synthesis. The diene was made from the anion of cyclopentadiene 74 and ethyl formate,18 and the enolate 76 transformed into the enol acetate 77. Diels-Alder addition of 62 and hydrolysis of the enol ester gave the adduct19 78. [Pg.285]

Nicolaou, K. C., Guy, R. K., Pitsinos, E. N., Wrasidlo, W. A water-soluble prodrug of taxol with self-assembling properties. Angew. Chem. Int. Ed. 1994. (in press)... [Pg.745]

Narasaka and coworkers have reported the IMDA reaction of 3-hydroxy-2-pyrone 34 (Scheme 36) with 4-hydroxy-2-butenoate 144, which was temporarily tethered with phenylboronic acid, to provide a single cycloadduct 147 in 75% yield <91S1171>. This elegant strategy was further elaborated by Nicolaou and coworkers for the synthesis of 151 as the C-ring intermediate in their initial synthetic endeavors towards the total synthesis of taxol <92JCS(CC)1118 95JACS624>. [Pg.21]

KC Nicolaou, D Vourloumis, T Li. Designed epothilones combinatorial synthesis, tubulin assembly properties, and cytotoxic action against taxol-resistant tumor cells. Angew Chem Int Ed 36 2097-2103, 1997. [Pg.166]

An initial peak of the taxol excitement was reached in 1994 when the first two total syntheses by R. A. Holton et al. [5] (Florida State University) and K. C. Nicolaou et al. [Pg.296]

Scheme 1. Semisynthesis of taxol (paclitaxel) and taxotere from protected baccatin III according to Holton and Ojima (cf. [la-d]) strategic bond cleavages for the syntheses of Holton et al., [5] Nicolaou et al.,... Scheme 1. Semisynthesis of taxol (paclitaxel) and taxotere from protected baccatin III according to Holton and Ojima (cf. [la-d]) strategic bond cleavages for the syntheses of Holton et al., [5] Nicolaou et al.,...
Scheme 3. Total synthesis of taxol according to Nicolaou et al. [6] Taxol numbering (Scheme 1) is used. Scheme 3. Total synthesis of taxol according to Nicolaou et al. [6] Taxol numbering (Scheme 1) is used.
Inspired by these results, Nicolaou et al. used a temporary boronate tether to overcome the undesired regiochemical bias in the intermolecular Diels-Alder reaction of diene 56 and dienophile 57, required for their approach to the C-ring of taxol 58 [21a, b, 24], Thermolysis of a benzene solution of 56 and 57 in the presence of PhB(OH)2 under dehydrating conditions provided the cycloadduct 59 in 79% yield (77% conversion) after transacetalization of the boron tether with 2,2-dimethylpropane-l,3-diol and intramolecular acyl transfer to the less strained [4.3.0]bicyclic system. This was further elaborated to an advanced intermediate in the ultimately successful synthesis of taxol (Scheme 10-21) [21c]. [Pg.292]

Scheme 10-21 Nicolaou et al. used a boron-tethered cycloaddition to construct the C-ring of taxol. Scheme 10-21 Nicolaou et al. used a boron-tethered cycloaddition to construct the C-ring of taxol.

See other pages where Taxol Nicolaou is mentioned: [Pg.92]    [Pg.1]    [Pg.92]    [Pg.1]    [Pg.656]    [Pg.657]    [Pg.152]    [Pg.195]    [Pg.195]    [Pg.195]    [Pg.195]    [Pg.60]    [Pg.407]    [Pg.650]    [Pg.886]    [Pg.887]    [Pg.52]    [Pg.253]    [Pg.265]    [Pg.428]    [Pg.286]    [Pg.229]    [Pg.190]    [Pg.235]    [Pg.496]    [Pg.3]    [Pg.253]    [Pg.265]    [Pg.94]    [Pg.172]    [Pg.186]    [Pg.197]    [Pg.614]    [Pg.164]    [Pg.298]    [Pg.303]    [Pg.490]   


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