Synthetic approaches to 2-tetralones

Mechanistic studies on the CAN-mediated intramolecular cyclization of δ-aryl-β-dicarbonyl compounds

“…They are typically synthesized through transition-metal-mediated processes or preformed tetralin or naphthyl precursors [8–9]. Radical approaches can also be used to synthesize substituted 2-tetralones, and single-electron oxidations employing δ-aryl-β-dicarbonyl compounds have been carried out on arenes containing pendant β-ketoesters [10–11].…”

Polyvalent iodine in organic chemistry: Recent developments, 2002–2005

“…The same type of intramolecular cyclization is realized with the formation of C C bond [49,50] (Scheme 17).…”

Bifunctional Brønsted Base Catalyst Enables Regio‐, Diastereo‐, and Enantioselective Cα‐Alkylation of β‐Tetralones and Related Aromatic‐Ring‐Fused Cycloalkanones

“…Syntheses of many bioactive compounds with polycyclic structures,i ncluding homoerythrina alkaloids, [1] morphan derivatives, [2] glucocorticoid receptors, [3] and stradiols, [4] among others, [5] have employed b-tetralones.H owever, this interest did not translate into avariety of approaches for the asymmetric synthesis of substituted b-tetralones.M ost approaches for the a/a'-functionalization of b-tetralones so far documented exploit the idea of Stork et al [6] which involves condensation with ac hiral amine and subsequent C-alkylation of the resulting enamine,typically by addition to aMichael acceptor. [7] One complication, for any nonsymmetric cycloalkanone,ist hat enolization may occur at either the a or a' site.Inthis context, Blarer and Seebach [8] reported that the reaction with nitrostyrenes of the enamine derived from (S)-2-methoxymethylpyrrolidine,a nd the respective b-tetralone produced in moderate yields the a'-adduct predominantly (a/a' from 1:4t o1 :20) with generally good diastereoand enantioselectivity after hydrolysis of the resulting iminium species (Scheme 1a).…”

“…These results suggest that formation of the tricycles 25/25' ' through aMichael/Henry cascade [24,25] not only proceeds in high stereoselectivity,b ut also involves some kinetic resolution process.S imilarly,t reatment of 14 (d.r. [5,28] In addition, hexahydro-benzo[e]indoles,h eterocyclic cores present in various biologically active compounds, [29] could also be prepared. [16] Thec onfiguration of 26/26' ' was assigned by analogy.Inadifferent example,w hen 14 was treated with acrolein in the presence of C2 at room temperature,the Michael addition product 27 was isolated in 80 %y ield.…”