- Steps towards a practical synthesis of macrocyclic bisbenzylisoquinolines
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There are more than 400-reported bisbenzylisoquinoline alkaloids, many with interesting biological activity, but the reported syntheses are long and low yielding. As a result, there have been no systematic attempts at exploitation of the potential therapeutic applications. The concept of a sulfur 'stitch', restricting the conformational freedom of intermediates in the synthesis, will potentially allow analogues of the natural products to be prepared using relatively efficient routes. The synthesis of intermediate sulfur heterocycles is reported, based on 2,8-dimethylphenoxathiin, leading via 2,8-bis(bromomethyl) phenoxathiin-10,10-dioxide to a synthesis of 3,4,8,9-tetrahydro-13-oxa-6-thia-2, 10-diazapentacene, a key potential intermediate on the route to a variety of macrocyclic bisbenzylisoquinolines.
- Al-Hiari, Yusuf M.,Bennett, Stephen J.,Cox, Brian,Davies, Robert J.,Khalaf, Abedawn I.,Waigh, Roger D.,Worsley, Alan J.
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p. 647 - 659
(2007/10/03)
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- Spirodienones. Part 6. Spiro-γ-lactones from 1-Benzyltetrahydro-1-naphthoic Acids and a 1-Benzyltetrahydroisoquinoline-1-carboxylic Acid
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The synthetic potential of spiro-γ-lactones derived from 1-benzyl-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acids is discussed.Previous oxidation studies have suggested that, for lactone formation, these acids should have no oxygen substituents at the 6 or 7 position of the isoquinoline, but such compounds have rarely been described.A series of 1-benzyl-1,2,3,4-tetrahydronaphthalene-1-carboxylic acids were prepared as model compounds, and were oxidised in good yield by chemical or electrochemical methods to spiro-γ-lactones.Routes to corresponding tetrahydroisoquinoline-1-carboxylic acids, unsubstituted on the isoquinoline benzene ring, were developed.In general, oxidation of these acids did not give lactones, but bromination of one phenolic acid did yield a dibromo spiro-γ-lactone.
- Coutts, Ian G. C.,Hadfield, John A.,Huddleston, Patrick R.
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p. 2472 - 2500
(2007/10/02)
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