A PHP Error was encountered

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

Synthesis and unexpected oxidization of the tricyclic core of ugibohlin, isophakellin, and styloguanidine. | LitMetric

A series of 4-substituted 5,6,7,9-tetrahydropyrrolo[2,3-f]indolizin-9-ones, representing the tricyclic core skeleton of ugibohlin, isophakellin, and styloguanidine, were synthesized via an intramolecular Vilsmeier-Haack reaction. This reaction allows the chemoselective C-C bond formation between the pyrrole C3 and proline C5 of N-[(pyrrol-2-yl)carbonyl]prolinamides to construct the B-ring without the protection of the pyrrole nitrogen. Unexpected oxidizative property of the tricyclic core skeleton was observed, which could illuminate understanding of the biological formation of these marine secondary metabolites.

Download full-text PDF

Source
http://dx.doi.org/10.1021/jo401911aDOI Listing

Publication Analysis

Top Keywords

tricyclic core
12
ugibohlin isophakellin
8
isophakellin styloguanidine
8
core skeleton
8
synthesis unexpected
4
unexpected oxidization
4
oxidization tricyclic
4
core ugibohlin
4
styloguanidine series
4
series 4-substituted
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!