Synthesis of the core ring system of the yuzurimine-type Daphniphyllum alkaloids by cascade condensation, cyclization, cycloaddition chemistry

I Coldham, L Watson, H Adams…

Index: Coldham, Iain; Jana, Samaresh; Watson, Luke; Martin, Nathaniel G. Organic and Biomolecular Chemistry, 2009 , vol. 7, # 8 p. 1674 - 1679

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Citation Number: 29

Abstract

Addition of hydroxylamine to substituted 4-chlorobutanals gives intermediate nitrones that undergo tandem cyclization and then intramolecular dipolar cycloaddition to give the core ring system of the yuzurimine-type natural products. Ring-opening of the isoxazolidines gives amino alcohols that can be converted to 1, 3-oxazines, representing the tetracyclic core of alkaloids such as daphcalycic acid and daphcalycine.