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 enantioselective total syntheses of the potent immunosuppressant FR901483 (1) and its 8-epimer (47) have been accomplished. Our approach features the use of building block 6 as the chiron, the application of the one-pot amide reductive bis-alkylation method to construct the chiral aza-quaternary center (dr = 9:1), regio- and diastereoselective intramolecular aldol reaction to build the bridged ring, and RCM to form the 3-pyrrolin-2-one ring.
Download full-text PDF |
Source |
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http://dx.doi.org/10.1021/jo302362b | DOI Listing |
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