<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1870-249X</journal-id>
<journal-title><![CDATA[Journal of the Mexican Chemical Society]]></journal-title>
<abbrev-journal-title><![CDATA[J. Mex. Chem. Soc]]></abbrev-journal-title>
<issn>1870-249X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Química de México A.C.]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1870-249X2007000400009</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Synthesis and Absolute Configuration of (20R)-20-Acetyl-23,24-bisnorcholanic Lactones Prepared from (E)-(20S,25R)- and (E)-(20S,25S)-20,23-Diacetylfurost-22-enes]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Hernández Linares]]></surname>
<given-names><![CDATA[Guadalupe]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Meza Reyes]]></surname>
<given-names><![CDATA[Socorro]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Montiel Smith]]></surname>
<given-names><![CDATA[Sara]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Sandoval Ramírez]]></surname>
<given-names><![CDATA[Jesús]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gómez Calvario]]></surname>
<given-names><![CDATA[Víctor]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Bernès]]></surname>
<given-names><![CDATA[Sylvain]]></given-names>
</name>
<xref ref-type="aff" rid="A03"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad del Istmo Escuela de Ingeniería Química ]]></institution>
<addr-line><![CDATA[Tehuantepec Oaxaca]]></addr-line>
<country>México</country>
</aff>
<aff id="A02">
<institution><![CDATA[,Benemérita Universidad Autónoma de Puebla Facultad de Ciencias Químicas ]]></institution>
<addr-line><![CDATA[Puebla ]]></addr-line>
<country>México</country>
</aff>
<aff id="A03">
<institution><![CDATA[,Universidad Autónoma de Nuevo León Facultad de Ciencias Químicas ]]></institution>
<addr-line><![CDATA[Monterrey Nuevo León]]></addr-line>
<country>México</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2007</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2007</year>
</pub-date>
<volume>51</volume>
<numero>4</numero>
<fpage>217</fpage>
<lpage>221</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1870-249X2007000400009&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1870-249X2007000400009&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1870-249X2007000400009&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[The synthesis of (20R)-20-acetyl-23,24-bisnorcholanic lactones from (E)-(20S,25R)- and (E)-(20S,25R)-20,23-diacetylfurost-22-enes (derived from diosgenin, hecogenin and sarsasapogenin) is reported. The configuration of the stereogenic center at C-20 was determined by NMR and single crystal X-ray diffraction studies. The lactones can be used in the synthesis of a variety of steroidal derivatives.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Se reporta la síntesis de lactonas (20R)-20-acetil-23,24-bisnorcolánicas a partir de (E)-(20S,25R)- y (E)-(20S,25R)-(E)-20,23-diacetilfurost-22-enos (obtenidos a partir de diosgenina, hecogenina y sarsasapogenina). La configuración del centro estereogénico C-20 fue determinada por estudios de RMN y difracción de rayos X de monocristal. Las lactonas pueden ser usadas en la síntesis de una variedad de derivados esteroidales.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Absolute configuration]]></kwd>
<kwd lng="en"><![CDATA[23,24-bisnorcholanic lactones]]></kwd>
<kwd lng="en"><![CDATA[20,23-diacetylfurost-22-enes]]></kwd>
<kwd lng="en"><![CDATA[molecular structure]]></kwd>
<kwd lng="es"><![CDATA[Configuración absoluta]]></kwd>
<kwd lng="es"><![CDATA[lactonas 23,24-bisnorcolánicas]]></kwd>
<kwd lng="es"><![CDATA[20,23-diacetilfurost-22-enos]]></kwd>
<kwd lng="es"><![CDATA[estructura molecular]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[  	    <p align="justify"><font face="verdana" size="4">Article</font></p>      <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="center"><font face="verdana" size="4"><b>Synthesis and Absolute Configuration of (20<i>R</i>)&#45;20&#45;Acetyl&#45;23,24&#45;bisnorcholanic Lactones Prepared from (<i>E</i>)&#45;(20<i>S</i>,25<i>R</i>)&#45; and (<i>E</i>)&#45;(20<i>S</i>,25<i>S</i>)&#45;20,23&#45;Diacetylfurost&#45;22&#45;enes</b></font></p>  	    <p align="center"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="center"><font face="verdana" size="2"><b>Guadalupe Hern&aacute;ndez Linares,<sup>1</sup>* Socorro Meza Reyes,<sup>2</sup>* Sara Montiel Smith,<sup>2</sup> Jes&uacute;s Sandoval Ram&iacute;rez,<sup>2</sup> V&iacute;ctor G&oacute;mez Calvario<sup>2</sup> and Sylvain Bern&egrave;s<sup>3</sup></b></font></p>  	    <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="justify"><font face="verdana" size="2"><sup>1</sup>&nbsp;<i>Escuela de Ingenier&iacute;a Qu&iacute;mica. Universidad del Istmo. Ciudad Universitaria, Sta. Cruz Tagolaba, Sto. Domingo Tehuantepec, Oaxaca, M&eacute;xico. CP 70760.</i></font></p>  	    <p align="justify"><font face="verdana" size="2"><sup>2</sup>&nbsp;<i>Facultad de Ciencias Qu&iacute;micas. Benem&eacute;rita Universidad Aut&oacute;noma de Puebla, Ciudad Universitaria, San Manuel, Puebla, Pue., M&eacute;xico. CP 72570.</i></font></p>  	    <p align="justify"><font face="verdana" size="2"><sup>3</sup>&nbsp;<i>Facultad de Ciencias Qu&iacute;micas. Universidad Aut&oacute;noma de Nuevo Le&oacute;n, Guerrero y Progreso S/N Col. Trevi&ntilde;o, Monterrey, Nuevo Le&oacute;n, M&eacute;xico. CP 64570</i>.</font></p>  	    ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="justify"><font face="verdana" size="2">Recibido el 15 de agosto de 2007    <br> 	Aceptado el 26 de noviembre de 2007</font></p>  	    <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p>  	    <p align="justify"><font face="verdana" size="2">The synthesis of (20<i>R</i>)&#45;20&#45;acetyl&#45;23,24&#45;bisnorcholanic lactones from (<i>E</i>)&#45;(20<i>S</i>,25<i>R</i>)&#45; and (<i>E</i>)&#45;(20<i>S</i>,25<i>R</i>)&#45;20,23&#45;diacetylfurost&#45;22&#45;enes (derived from diosgenin, hecogenin and sarsasapogenin) is reported. The configuration of the stereogenic center at C&#45;20 was determined by NMR and single crystal X&#45;ray diffraction studies. The lactones can be used in the synthesis of a variety of steroidal derivatives.</font></p>  	    <p align="justify"><font face="verdana" size="2"><b>Keywords:</b> Absolute configuration; 23,24&#45;bisnorcholanic lactones; 20,23&#45;diacetylfurost&#45;22&#45;enes; molecular structure.</font></p>  	    <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>  	    <p align="justify"><font face="verdana" size="2">Se reporta la s&iacute;ntesis de lactonas (20<i>R</i>)&#45;20&#45;acetil&#45;23,24&#45;bisnorcol&aacute;nicas a partir de (<i>E</i>)&#45;(20<i>S</i>,25<i>R</i>)&#45; y (<i>E</i>)&#45;(20S,25R)&#45;(E)&#45;20,23&#45;diacetilfurost&#45;22&#45;enos (obtenidos a partir de diosgenina, hecogenina y sarsasapogenina). La configuraci&oacute;n del centro estereog&eacute;nico C&#45;20 fue determinada por estudios de RMN y difracci&oacute;n de rayos X de monocristal. Las lactonas pueden ser usadas en la s&iacute;ntesis de una variedad de derivados esteroidales.</font></p>  	    ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2"><b>Palabras clave:</b> Configuraci&oacute;n absoluta; lactonas 23,24&#45;bisnorcol&aacute;nicas; 20,23&#45;diacetilfurost&#45;22&#45;enos; estructura molecular.</font></p>  	    <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="justify"><font face="verdana" size="2"><a href="/pdf/jmcs/v51n4/v51n4a9.pdf" target="_blank">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>  	    <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="justify"><font face="verdana" size="2"><b>Acknowledgments</b></font></p>  	    <p align="justify"><font face="verdana" size="2">The authors thank VIEP &#45; BUAP for financial support (Grant 43/NAT/06&#45;G) and for scholarships granted to VG.C.</font></p>  	    <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>  	    <p align="justify"><font face="verdana" size="2"><b>References</b></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">1.&nbsp;a) Fieser, L.; Fieser, M. <i>Steroids</i> Reinhold, San Francisco, <b>1959,</b> p. 814.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976063&pid=S1870-249X200700040000900001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --> b) Corcoran, J. W.; Hirschmann, H. <i>J. Am. Chem. Soc.</i> <b>1956,</b> <i>78,</i> 2325.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976064&pid=S1870-249X200700040000900002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">2.&nbsp;a) Gonz&aacute;lez, A. G.; Freire, R.; Francisco, C. G.; Salazar, J. A.; Su&aacute;rez E. <i>Tetrahedron</i> <b>1973,</b> <i>29,</i> 1731.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976066&pid=S1870-249X200700040000900003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --> b) Ahmad, V. U.; Zaman, S. M. K.; Shameel, S.; Perveen, S.; Ali, Shaista. <i>Phytochemistry</i> <b>1998,</b> 50, 481.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976067&pid=S1870-249X200700040000900004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --> c) Zheng, Q. A.; Zhang, Y. J.; Li, H. Z.; Yang, C.R. <i>Steroids</i> <b>2004,</b> 69, 111.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976068&pid=S1870-249X200700040000900005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">3.&nbsp;Gonz&aacute;lez, A. G.; Darias, V.; Su&aacute;rez, M. C.; Janssen, K. <i>Il F&aacute;rmaco</i> <b>1983,</b> <i>38,</i> 3.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976070&pid=S1870-249X200700040000900006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">4.&nbsp;a) Gashchenko, L. G.; Maksimow, V. I.; Alekseeva, L. M. <i>Khim. Farm. Zh.</i> <b>1971,</b> 5, 20;    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976072&pid=S1870-249X200700040000900007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --> b) <i>Chem. Abstr.</i> <b>1971,</b> <i>75,</i> 64088.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4976073&pid=S1870-249X200700040000900008&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    ]]></body>
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