Tandem Hock and Friedel – Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

Abstract
The Hock cleavage, which is compatible with tandem processes, was applied to the synthesis of 1-aryltetralines through a one-pot transformation from readily available benzyl(prenyl)malonate substrates. After the photooxygenation of the prenyl moiety, the resulting hydroperoxide was directly engaged in a Hock cleavage by adding a Lewis acid. The presence of an aromatic nucleophile in the reaction mixture and that of a benzyl moiety on the substrate resulted in tandem Friedel–Crafts reactions to form the 1-aryltetraline products. These compounds share a close analogy to the cyclolignan natural products. Experimental observations and a DFT study support the involvement of an aldehyde intermediate during the Friedel–Crafts reactions, rather than an oxocarbenium.

Beilstein J. Org. Chem. 2024, 20, 162–169. doi:10.3762/bjoc.20.15

Source: Beilstein Journal of Organic Chemistry - January 25, 2024 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: 1-aryltetralines Friedel – Crafts reaction Hock rearrangement oxidative cleavage tandem reactions Full Research Paper Source Type: research