Severity: Warning
Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 176
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3122
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
The stereoselective total synthesis of cytotoxic marine macrolide callyspongiolide has been reported. The 14-membered macrolactone ring along with -olefin in the molecule was constructed via an intramolecular Horner-Wadsworth-Emmons olefination in a -selective fashion. The other -olefinic moiety as well as the C9 stereocenter was introduced via stereoselective addition of the methyl group in an S2' fashion. The C5 stereocenter was installed via Sakurai allylation, whereas the C7 center was fixed by Jacobsen hydrolytic kinetic resolution. The C12 methyl and C13 hydroxy centers were fixed via Macmillan coupling reaction. The macrolactone core with a vinyl iodide side chain was coupled with the known alkyne fragment to complete the synthesis.
Download full-text PDF |
Source |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643460 | PMC |
http://dx.doi.org/10.1021/acsomega.8b02156 | DOI Listing |
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