Tetrahedron: Asymmetry

Synthetic studies on zoapatanol: Construction of oxepanes via an intramolecular 1, 3-dipolar cycloaddition strategy

TKM Shing, CH Wong, T Yip

Index: Shing, Tony K.M.; Wong, Ching-Hung; Yip, Ting Tetrahedron Asymmetry, 1996 , vol. 7, # 5 p. 1323 - 1340

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Citation Number: 49

Abstract

The nitrones derived from β-allyloxyaldehydes with a β-quaternary centre cyclized to give six- instead of seven-membered O-heterocycles exclusively whereas a nitrile oxide derived from a γ-allyloxyaldehyde with a γ-quaternary center cyclized to yield an oxepane ring as the sole product. Using the latter intramolecular nitrile oxide cycloaddition as the key step, optically active oxepane 5, which is a suitable intermediate for a synthesis of zoapatanol 1, has ...