Ti(III)-Mediated Radical-Induced Approach to a Bicyclic δ-Lactone with a Bridgehead β-Hydroxy Group

Chakraborty, Tushar ; Das, Dipendu ; Khan, Hina (2018) Ti(III)-Mediated Radical-Induced Approach to a Bicyclic δ-Lactone with a Bridgehead β-Hydroxy Group Synthesis, 50 (15). pp. 3006-3014. ISSN 0039-7881

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Official URL: http://doi.org/10.1055/s-0037-1609586

Related URL: http://dx.doi.org/10.1055/s-0037-1609586

Abstract

Herein, we portray a synthetic route to a bicyclic lactone containing a bridgehead hydroxy group, a structure that is present in many natural products of biological and medicinal relevance. Ethyl (E)-3-(dimethylphenylsilyl)-7,8-epoxyoct-2-enoate underwent radical-mediated­ reductive epoxide opening with concomitant intramolecular cyclization using Cp2Ti(III)Cl to give cis-6-(dimethylphenylsilyl)-3-oxabicyclo[4.3.0]nonan-4-one, a bicyclic lactone with a bridgehead silyl group serving as a masked hydroxy group. Furthermore, the bridgehead C–Si bond underwent stereoretentive oxidative cleavage to give cis-6-hydroxy-3-oxabicyclo[4.3.0]nonan-4-one in high yield under Tamao–Fleming oxidation conditions; this demonstrates the potential utility of this strategy in the synthesis of many natural products bearing similar hydroxylated bridgehead chiral center embedded in a bicyclic lactone framework.

Item Type:Article
Source:Copyright of this article belongs to Georg Thieme Verlag KG
Keywords:Quaternary center; bridgehead hydroxy; Cp2TiCl; bicyclic lactone; radical cyclization; Tamao–Fleming oxidation
ID Code:131079
Deposited On:02 Dec 2022 09:55
Last Modified:02 Dec 2022 09:55

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