ortho-Diquaternary aromatic compounds. III. Syntheses and reactions of polyalkyltetralones and derivatives

Barclay, L. R. C.; Adams, Keir Leigh; Foote, H. M.; Sanford, Emerson C.; Young, Robert H.

doi:10.1139/v70-465

Cited by 8 publications

(1 citation statement)

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“…It has been reported that conversion of a keto-tetrahydronaphthalene to a dihydronaphthalene can successfully be performed using POCl 3 /pyridine . Thus, reaction of keto-tetrahydronaphthalene 22 , prepared in four steps and 50% overall yield from p -tolylacetic acid, with 14 using AlCl 3 (4.0 equiv) afforded 23 in 62% yield. Olefination of 23 with methyltriphenylphosphonium ylide afforded olefin 24 in 57% yield.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Novel Retinoid X Receptor-Selective Retinoids

et al. 2001

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Retinoids 1-5 have been identified as potent RXR agonists for evaluation in the treatment of non-insulin-dependent (type II) diabetes mellitus (NIDDM). Highly convergent syntheses of 1-5 have been developed. The core tetrahydronaphthalene 7, employed in the synthesis of 1 and 2, was prepared in 98% yield using an AlCl(3)-catalyzed (0.03 equiv) Friedel-Crafts alkylation of toluene with 2,5-dichloro-2,5-dimethylhexane 6. A nitromethane-mediated Fridel-Crafts acylation of 7 with chloromethylnicotinate 9 was developed to prepare ketone 10 in 68% yield. Chelate-controlled addition of MeMgCl to 10 followed by dehydration afforded olefin 11 in 65% yield. Cyclopropanation of 11 with trimethylsulfoxonium ylide, followed by saponification, completed a five-step synthesis of 1 in 33% yield. FeCl(3)-catalyzed (0.05 equiv) Friedel-Crafts acylation of 7 with chloromethylterephthalate 14 afforded ketone 15 in 81% yield. Saponification of 15 and reaction with 50% aqueous NH(2)OH in AcOH afforded a 9:1 mixture of cis and trans oximes, from which the desired cis-oxime 2 was isolated in 43% yield. The core bromo-dihydronaphthalene 29 required for the synthesis of 3-5 was prepared by a Shapiro reaction. Transmetalation of 29 and reaction with Weinreb amides 30b or 36 afforded ketones 32 and 37, which were converted into 3-5 using chemistry comparable to the tetrahydronaphthylene series. Suzuki coupling of boronic acids 41 and 42 with vinyl triflate 43 provided an alternative approach to the synthesis of this class of compounds.

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Section: Resultsmentioning

confidence: 99%

Synthesis of Novel Retinoid X Receptor-Selective Retinoids

et al. 2001

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Polare Bromwasserstoff‐Addition an Olefine, I. Bromwasserstoff‐Addition an 1,1,4,4‐Tetramethyl‐1,4‐dihydronaphthalin: Synthesen von Ausgangs‐ und Reaktionsprodukten; Produktbilanz und sterischer Verlauf der Reaktion

1978

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Syntheses of Starting and Reaction Products; Balance of Products and Sterical Course of the ReactionSyntheses of 1,1,4,4-tetramethyl-1,4-dihydronaphthalene (1) and the selectively deuterated derivatives 8 and 9 are reported. Addition reactions of 1, especially the polar addition of hydrogen bromide, were investigated. In the reaction of 1 with hydrogen bromide in acetic acid/chloroform, besides the regular addition product 11, the rearranged products 7, 19 and 20 were isolated,the formation of which obviously is due to the isomerisation of the carbenium ion A to the tertiary carbenium ions B and C. As precursors of these carbenium ions the compounds 2, 3, 4, 5, 7, 12, 13 and 15 were synthesized in order to study the formation and transformation of A, B and C independently. O n the basis of these results the predominant reaction products of 1 with hydrogen bromide were identified and a balance of products for this reaction was established. The sterical course of the addition of hydrogen bromide to 1 was determined: 1 adds deuteriumbromide in [I-D,]acetic acid/deuteriochloroform according to 'H-NMR predominantly in an unti addition; the synlanti ratio as well as the addition/rearrangement ratio are, however, strongly dependent on the reaction conditions (cf. *)),

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