Editing Paclitaxel (section)

===Total synthesis===
{{Main|Paclitaxel total synthesis}}

[[Image:Taxol number.svg|thumb|class=skin-invert-image|Paclitaxel, with rings labeled and accepted numbering scheme shown.]]
By 1992, at least thirty academic research teams globally were working to achieve a [[total synthesis]] of this [[natural product]], with the synthesis proceeding from simple natural products and other readily available starting materials.<ref name=Hall2003>{{cite journal | vauthors = Hall N | title = Creating complexity—the beauty and logic of synthesis | journal = Chemical Communications | issue = 6 | pages = 661–664 | date = March 2003 | pmid = 12703766 | doi = 10.1039/b212248k }}</ref> This total synthesis effort was motivated primarily by the desire to generate new chemical understanding, rather than with an expectation of the practical commercial production of paclitaxel. The first laboratories to complete the total synthesis from much less complex starting materials were the research groups of [[Robert A. Holton]], who had the [[Holton taxol total synthesis|first article to be accepted for publication]], and of [[K. C. Nicolaou]] who had the [[Nicolaou Taxol total synthesis|first article to appear in print]] (by a week, on 7 February 1994). Though the Holton submission preceded the Nicolaou by a month (21 December 1993 versus 24 January 1994),<ref>See N. Hall, ibid. See also the [[American Chemical Society]] publication [[Chemical and Engineering News]] (C&EN), 21 February 1994, page 32, and primary citations appearing at Holton and Nicolaou taxol total synthesis articles.</ref> the near coincidence of the publications arising from each of these massive, multiyear efforts—11–18 authors appearing on each of the February 1994 publications—has led the ending of the race to be termed a "tie"<ref name=Flam1994>{{cite journal | vauthors = Flam F | title = Race to synthesize taxol ends in a tie | journal = Science | volume = 263 | issue = 5149 | pages = 911 | date = February 1994 | pmid = 7906053 | doi = 10.1126/science.7906053 | author-link = Faye Flam | bibcode = 1994Sci...263..911F }}</ref> or a "photo finish",<ref name=Hall2003/> though each group has argued that their synthetic strategy and tactics were superior.<ref name=Flam1994/>

As of 2006, five additional research groups had reported total syntheses of paclitaxel: [[Wender Taxol total synthesis|Wender et al.]] in 1997, and [[Kuwajima Taxol total synthesis|Kuwajima et al.]] and [[Mukaiyama Taxol total synthesis|Mukaiyama et al.]] in 1998 with further [[linear synthesis|linear syntheses]], and [[Danishefsky Taxol total synthesis|Danishefsky et al.]] in 1996 and [[Takahashi Taxol total synthesis|Takahashi et al.]] in 2006 with further [[convergent synthesis|convergent syntheses]].{{update inline|date=March 2017}} As of that date, all strategies had aimed to prepare a 10-deacetylbaccatin-type core containing the ABCD ring system, followed generally by last stage addition of the "tail" to the 13-[[hydroxyl group]].<ref name=Hall2003/>

While the "political climate surrounding [paclitaxel] and [the Pacific yew] in the early 1990s ... helped bolster [a] link between total synthesis and the [paclitaxel] supply problem," and though total synthesis activities were a requisite to explore the [[structure-activity relationship]]s of paclitaxel via generation of analogs for testing, the total synthesis efforts were never seen "as a serious commercial route" to provide significant quantities of the natural product for medical testing or therapeutic use.{{sfn|Goodman|Walsh|2001|pp=179–182}}