Synthesis of Methoxynor Polyisoprenoid Alcohols by Alkylation of (3-Methoxyallyl)lithium Reagents

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Title:Synthesis of Methoxynor Polyisoprenoid Alcohols by Alkylation of (3-Methoxyallyl)lithium Reagents
Creators:
Jin, Qingwu
Coates, Robert M.
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 67, 1, pp. 55-74
Uncontrolled Keywords:Alkylations, Enol ethers, Isoprenoids, Terpenoids, Polyenes, Lithiations, Allyllithium reagents

Abstract

A series of six methyl enol ether analogs <strong>8</strong>-<strong>13</strong> of geraniol, (<i>E</i>,<i>E</i>)-farnesol, and (<i>E</i>,<i>E</i>,<i>E</i>)-geranylgeraniol was synthesized from a group of three allylic methyl ethers and three allylic chlorides. Lithiation of the 1-methyl-, or 1-alkenylvinyl ethers with <i>sec</i>-butyllithium at -78 °C followed by alkylations of the resulting (<i>Z</i>)-(3-methoxyallyl)lithium reagents afforded the six possible Z-configured(trans) methoxynor polyprenyl benzyl ethers bearing the methoxy substituent at the internal and terminal double bonds with high Z/E ratios (5 : 1-31 : 1) and 47-80% yields. Reductive cleavage of the benzyl groups with lithium in liquid ammonia gave the corresponding methoxynor polyprenols. 11-Methoxy-18-nor and 7-methoxy-19-nor geranylgeraniols (<strong>13</strong> and <strong>12</strong>) were converted to the corresponding diphosphates, <strong>7</strong> and <strong>32</strong>, by the Poulter displacement method. The stability of the enol ether in <strong>7</strong> in aqueous solution at pH 8 was verified by NMR analyses. The diphosphates of the methoxynor polyprenols may prove useful as substrate analogs for terpene synthases to capture transient intermediates in cyclization reactions catalyzed by these enzymes. <p>

Title:Synthesis of Methoxynor Polyisoprenoid Alcohols by Alkylation of (3-Methoxyallyl)lithium Reagents
Creators:
Jin, Qingwu
Coates, Robert M.
Uncontrolled Keywords:Alkylations, Enol ethers, Isoprenoids, Terpenoids, Polyenes, Lithiations, Allyllithium reagents
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:67
Number:1
Page Range:pp. 55-74
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20020055UNSPECIFIED
ID Code:1905
Item Type:Article
Deposited On:06 Feb 2009 17:13
Last Modified:06 Feb 2009 16:13

Citation

Jin, Qingwu; Coates, Robert M. (2002) Synthesis of Methoxynor Polyisoprenoid Alcohols by Alkylation of (3-Methoxyallyl)lithium Reagents. Collection of Czechoslovak Chemical Communications, 67 (1). pp. 55-74. ISSN 0010-0765

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