(3-Methylene-2,3-dihydronaphtho[2,3-b][1,4]dioxin-2-yl)methanol was unexpectedly achieved as the main reaction product while applying a standard Johnson–Corey–Chaykovsky procedure to the 2,3-dihydronaphtho[2,3-b][1,4]dioxine-2-carbaldehyde, aiming at obtaining the corresponding epoxide. The structure of the recovered compound was confirmed through NMR and HRMS, the melting point was measured by DSC, and the organic purity was assessed using HPLC. We hypothesized the possible mechanism for the obtainment of this side product, which should involve the opening of the dioxane ring soon after the nucleophilic attack of the ylide to the carbonyl function. The consequent transfer of the negative charge allows the achievement of the phenolate function. The tautomer further rearranges, forming the unstable oxirane, which opening is favored by the acidic phenolic function, thus closing into the more stable six-membered ring compound. We confirmed the hypothesized reaction mechanism by applying the same reaction conditions while starting from the corresponding methyl ketone. This undesired compound, easily and quantitatively obtained by standard Johnson–Corey–Chaykovsky conditions, could pave the way to a new methodology for the obtainment of 2,3-disubstituted 1,4-naphthodioxanes, further derivatizable.

(3-Methylene-2,3-dihydronaphtho[2,3-b][1,4]dioxin-2-yl)methanol / L. Suigo, G. Lodigiani, V. Straniero, E. Valoti. - In: MOLBANK. - ISSN 1422-8599. - 2022:4(2022 Dec), pp. M1521.1-M1521.8. [10.3390/M1521]

(3-Methylene-2,3-dihydronaphtho[2,3-b][1,4]dioxin-2-yl)methanol

L. Suigo
Primo
;
G. Lodigiani
Secondo
;
V. Straniero
Penultimo
;
E. Valoti
Ultimo
2022

Abstract

(3-Methylene-2,3-dihydronaphtho[2,3-b][1,4]dioxin-2-yl)methanol was unexpectedly achieved as the main reaction product while applying a standard Johnson–Corey–Chaykovsky procedure to the 2,3-dihydronaphtho[2,3-b][1,4]dioxine-2-carbaldehyde, aiming at obtaining the corresponding epoxide. The structure of the recovered compound was confirmed through NMR and HRMS, the melting point was measured by DSC, and the organic purity was assessed using HPLC. We hypothesized the possible mechanism for the obtainment of this side product, which should involve the opening of the dioxane ring soon after the nucleophilic attack of the ylide to the carbonyl function. The consequent transfer of the negative charge allows the achievement of the phenolate function. The tautomer further rearranges, forming the unstable oxirane, which opening is favored by the acidic phenolic function, thus closing into the more stable six-membered ring compound. We confirmed the hypothesized reaction mechanism by applying the same reaction conditions while starting from the corresponding methyl ketone. This undesired compound, easily and quantitatively obtained by standard Johnson–Corey–Chaykovsky conditions, could pave the way to a new methodology for the obtainment of 2,3-disubstituted 1,4-naphthodioxanes, further derivatizable.
1,4-naphthodioxane; dioxane ring opening; Corey–Chaykovsky epoxidation; Corey–Chaykovsky byproducts;
Settore CHIM/06 - Chimica Organica
Settore CHIM/08 - Chimica Farmaceutica
dic-2022
6-dic-2022
https://www.mdpi.com/1422-8599/2022/4/M1521
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/947749
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