Trapping of o-quinodimethane with p-quinones: synthesis of tetrahydro-1,4-anthracenediones

Abstract

. Can. J. Chem. 63, 3526 (1985). Previous work from our laboratory has been concerned with investigating the photochemical reactivity of the tetrahydro-1,4-napthalenedione system, both in solution and the solid state. The results obtained prompted us to extend our studies to the analogous tetrahydro-l,4-anthracenedione system. The most direct method of synthesis of the desired compounds is through Diels-Alder addition of o-quinodimethane to p-quinones. Because of the ease with which the adducts would be expected to undergo bis-enolization to the corresponding hydroquinones, their preparation requires mild, neutral conditions. After much experimentation, success was achieved using the Durst-Charlton sulfur dioxide extrusion method for generating o-quinodimethane from 3,6-dihydro-l,2-oxathiin-2-oxide. In situ trapping.using p-benzoquinone and other substituted p-quinones afforded the desired adducts in reasonable yields. In the case of duroquinone and 2,3-dimethyl-l,4-naphthalenedione, fluoride ion-catalyzed generation of o-quinodimethane from [o-[cu-(trimethylsilyl)methyl]benzyl]trimethylamrnoniurn bromide by the method of Ito also gave acceptable results; however, the bis-enolizable adducts were not stable under these eaction conditions. SYED ASKARI, SUSAN LEE, ROBERT R. PERKINS et JOHN R. SCHEFFER. Can. J. Chem. 63, 3526 (1985). Dans un travail anttrieur rtalist dans notre laboratoire, on a examine la rtactivitt photochimique du systeme titrahydronaphtalbnedione-1,4 tant en solution qu'a l'ttat solide. Les rtsultats obtenus nous ont incitt a Ctendre nos ttudes au systbrne analogue de la tttrahydroanthracenedione-1,4. La rntthode la plus directe de synthese des composts dtsirts implique une addition de Diels-Alder du o-quinodimtthane sur des p-quinones. Compte tenu du fait qu'il est A prCvoir que les adduits subiront facilement une bis-enolisation conduisant aux hydroquinones correspondantes, il est important d'utiliser des conditions

o-Quinodimethanes: Efficient Intermediates in Organic Synthesis

“…The route which has attracted more attention during the last years has been the oQDM generation via sultines, which were first synthesized by Durst and co-workers . Generation of oQDM from sultine ( 45 , 4,5-benzo-3,6-dihydro-1,2-oxathiin-2-oxide) has advantages over methods involving metals and dihalide, which cannot be used in the presence of reducible groups, or the fluoride ion catalyzed decomposition of { o -[(trimethylsilyl)methyl]benzyl}trimethylammonium bromide, because enolization can take place in the quinone adducts . On the other hand, while sulfone 46 is stable and requires temperatures around 300 °C to generate oQDM, sultines are known to require lower thermolysis temperature for the cheletropic elimination of SO 2 .…”

Attaching Organic Semiconductors to Gate Oxides: In Situ Assembly of Monolayer Field Effect Transistors

“…Reports of end functionalized linear acene syntheses are rare, apparently due to their difficulty in synthesis. , Here we devised a new and general synthesis (shown in Scheme ) that provides the substituted tetracene derivatives. The key step utilizes a Diels−Alder cyclization to couple two easily prepared pieces: the exocyclic diene , (derived from the in situ loss of sulfur dioxide from the cyclic sulfinate ester 2 ) and the 6,7-dimethoxy naphthoquinone 3 . , Instrumental for a clean synthesis is the intermediate reduction of the quinone to the tetrone. Reduction to the acene followed by unmasking of the hydroxyl groups with boron tribromide provides the target structure.…”

“…The key step utilizes a Diels-Alder cyclization to couple two easily prepared pieces: the exocyclic diene 22,23 (derived from the in situ loss of sulfur dioxide from the cyclic sulfinate ester 2) and the 6,7-dimethoxy naphthoquinone 3. 24,25 Instrumental for a clean synthesis is the intermediate reduction of the quinone to the tetrone. Reduction to the acene followed by unmasking of the hydroxyl groups with boron tribromide provides the target structure.…”

Palladium-Catalyzed Distannylation of ortho-Quinodimethanes

“…We first examined the reaction of simple o -quinodimethane, generated in situ from 2-[(trimethylsilyl)methyl]benzyl phenyl carbonate ( 1a ) and a fluoride ion, − with hexabutylditin ( 2 ) in the presence of bis( dibenzylideneacetone)palladium-diphenyl-2-pyridylphosphine (Ph 2 P(2-Py)) and observed that the exo -diene moiety was inserted into the Sn−Sn σ-bond to produce the distannylation product, α,α‘-bis(tributylstannyl)- o -xylene ( 3a ) in 55% yield (Scheme ). The reactions using other o -quinodimethane precursors or ligands also gave 3a , although the yields were rather low…”