Novel method for the synthesis of α- and β-halogenonaphthalenes by regioselective benzannulation of aryl(gem-dihalogenocyclopropyl)methanols: Application to the total synthesis of the lignan lactones, justicidin E and taiwanin C

DOI: 10.1039/P19960002157

Source and publish data:

Journal of the Chemical Society. Perkin transactions I p. 2157 - 2165 (1996)

Update date:2022-07-29

Topics:

Authors:

Tanabe, Yoo

Seko, Shinzo

Nishii, Yoshinori

Yoshida, Taichi

Utsumi, Naoka

Suzukamo, Gohfu

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Article abstract of DOI:10.1039/P19960002157

Acid treatment of two types of aryl(gem-dihalogenocyclopropyl)methanols (ADCMs) 1 and 3 gives α- and β-halogenonaphthalenes in good yields with excellent selectivity. These alternative annulations involve two distinctive types of highly regioselective acid-induced cyclopropane ring cleavage, wherein the preferential formation of more stable cationic intermediates determines the selectivity. The stereochemical mode of both the preparation and the annulation between diastereoisomers of an ADCM has been checked. As a demonstration of this annulation, a total synthesis of each of the natural lignan lactones, justicidin E 19 and taiwanin C 20, has also been performed. Since these 4-arylnaphthalenes are expected to exhibit biological activity, the anti-platelet activating factor (anti-PAF) activity of justicidin E has been assayed.