An approach toward novel bioactive natural products antroquinonols: de novo construction of the carbocyclic core
摘要:
A new, short, approach toward bioactive antroquinonols has been conceptualized wherein the key carbocyclic core has been readily assembled employing disposable norbornyl scaffold as the regio- and stereo-director and a Wittig olefination based strategy is projected for appending the farnesyl arm. (C) 2015 Elsevier Ltd. All rights reserved.
Acid-Induced Rearrangement Reactions of Reduced Benzoquinone Cyclopentadiene Cycloadducts
作者:Martin Eipert、Cäcilia Maichle-Mössmer、Martin E. Maier
DOI:10.1021/jo026238i
日期:2002.11.1
Several Diels-Alder adducts between benzoquinones and cyclopentadiene were reduced to the corresponding diols 7a-c and 11. Treatment of these diols with strong acid triggered a skeletal rearrangement reaction resulting in compounds 8a-c and 12 that contain a 4,8-methanoazulene substructure. In addition, a dyotropic-like rearrangement of the tetracyclic lactone 13 to the spiro-lactone 18 was observed. Five
Synthesis of New Type Diacetal Trioxa-Cage Compounds via an Intramolecular Nucleophilic Addition of the Hydroxy Group to the Carbonyl Oxide Group
作者:Hsien-Jen Wu、Ching-Shiun Chao、Chu-Chung Lin
DOI:10.1021/jo980632s
日期:1998.10.1
The synthesis of diacetal trioxa-cage compounds with a new type of skeleton is reported. Ozonolysis of the diols 2a-f, 21, 24, and 33 in CH2Cl2 at -78 degrees C followed by reduction with Me2S gave the diacetal trioxa-cages 3a-f, 22, 25, and 34 in 70-80% yields, respectively. A mechanism via an intramolecular nucleophilic addition of the hydroxy group of the diols to the carbonyl oxide group is proposed for the formation of the diacetal trioxa-cages. The effect of the number of carbon atoms at the bridge of the diols on the formation of the diacetal trioxa-cage skeleton was examined. Ozonolysis of the diols 13 and 15 under the same reaction conditions gave compounds 16 and 18, respectively. No detectable amount of the trioxa-cages 17 and 19 was obtained. For the synthesis of the diacetal trioxa-cages 28a-c and 31, which possess an alkene bond intact, ozonolysis of the diols 27a-c and 30 was performed by controlling the amount of ozone.
A New Synthesis of (-)-Aphanorphine by an Enantioconvergent Tactic
Catalytic Enantioselective Desymmetrization of Norbornenoquinones via C(sp<sup>2</sup>)–H Alkylation
作者:Rahul Sarkar、Santanu Mukherjee
DOI:10.1021/acs.orglett.6b03168
日期:2016.12.2
The enantioselective Diels–Alder (DA) reaction with monosubstituted p-benzoquinones is an unmet challenge. A new approach for the enantioselective synthesis of monosubstituted quinone-DA adducts is presented based on C(sp2)–H alkylative desymmetrization of meso-DA adducts. Catalyzed by a tertiary amino-thiourea derivative, this reaction utilizes nitroalkanes as the alkylating agents and generates densely
An approach toward novel bioactive natural products antroquinonols: de novo construction of the carbocyclic core
作者:Nagi Reddy Modugu、Goverdhan Mehta
DOI:10.1016/j.tetlet.2015.09.043
日期:2015.10
A new, short, approach toward bioactive antroquinonols has been conceptualized wherein the key carbocyclic core has been readily assembled employing disposable norbornyl scaffold as the regio- and stereo-director and a Wittig olefination based strategy is projected for appending the farnesyl arm. (C) 2015 Elsevier Ltd. All rights reserved.