<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-19T03:25:50Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/57703" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/57703</identifier><datestamp>2022-01-13T07:54:21Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131022</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Timothy F. Jamison.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Vilotijević, Ivan</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Dept. of Chemistry.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Chemistry</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2010-08-30T14:46:11Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2010-08-30T14:46:11Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2010</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2010</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/1721.1/57703</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">655778842</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2010.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Vita. Cataloged from PDF version of thesis.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references (p. 108-112).</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">[image] The proposed biogenesis of the ladder polyethers features a dramatic series of epoxide opening reactions, elegantly accounts for the structural and stereochemical features of all related natural products, and, in principle, could significantly simplify the synthesis of these extraordinarily complex molecules. In practice, however, such cascades are strongly disfavored, and non-natural directing groups must be covalently attached to each epoxide to overcome this inherent bias. We report herein a general method for directing group-free cascades that also supports the postulated biosynthesis. The two salient aspects of this strategy are a single design principle (a template) and a promoter that both donates and accepts hydrogen bonds. Water is the superior promoter, and it is most effective at approximately pH 7.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Ivan Vilotijević.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">Ph.D.</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="extent" lang="en_US">113 p.</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">M.I.T. theses are protected by 
copyright. They may be viewed from this source for any purpose, but 
reproduction or distribution in any format is prohibited without written 
permission. See provided URL for inquiries about permission.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri" lang="en_US">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Chemistry.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Directing group-free endo-selective epoxide-opening cascades</dim:field>
   <dim:field mdschema="dc" element="type" lang="en_US">Thesis</dim:field>
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	&lt;Language>eng&lt;/Language>
   	&lt;Title>Directing group-free endo-selective epoxide-opening cascades&lt;/Title>
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   	&lt;PublicationDate>2010&lt;/PublicationDate>
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        	&lt;DisplayName>Vilotijević, Ivan&lt;/DisplayName>
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            &lt;DisplayName>Massachusetts Institute of Technology&lt;/DisplayName>
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    &lt;License>http://dspace.mit.edu/handle/1721.1/7582&lt;/License>
    &lt;Keyword>Chemistry.&lt;/Keyword>
   	&lt;Abstract>[image] The proposed biogenesis of the ladder polyethers features a dramatic series of epoxide opening reactions, elegantly accounts for the structural and stereochemical features of all related natural products, and, in principle, could significantly simplify the synthesis of these extraordinarily complex molecules. In practice, however, such cascades are strongly disfavored, and non-natural directing groups must be covalently attached to each epoxide to overcome this inherent bias. We report herein a general method for directing group-free cascades that also supports the postulated biosynthesis. The two salient aspects of this strategy are a single design principle (a template) and a promoter that both donates and accepts hydrogen bonds. Water is the superior promoter, and it is most effective at approximately pH 7.&lt;/Abstract>
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