Stereochemistry of Diels-Alder Adducts. III. The Preparation and Rearrangement of Some Brominated Derivatives of Norbornanecarboxylic Acids

1959 ◽  
Vol 81 (11) ◽  
pp. 2762-2765 ◽  
Author(s):  
Werner R. Boehme
Keyword(s):  
1972 ◽  
Vol 50 (3) ◽  
pp. 371-380 ◽  
Author(s):  
J. A. Campbell ◽  
Donald Mackay ◽  
T. D. Sauer

The synthesis of a range of bicyclic Diels–Alder adducts (structures b) of cyclopentadiene with symmetrical and unsymmetrical azodicarbonyl compounds is described. Thermal isomerization of these adducts to the bicyclic 1,3,4-oxadiazines (structures c and d) is especially rapid with bulky acyl groups. In unsymmetrical adducts with acyl groups of markedly different size, the larger group dictates completely the direction of isomerization. Adducts with two different aroyl groups give both isomers.Spectroscopic properties of the adducts, the oxadiazines and the dihydro derivatives of the oxadiazines are described.


1994 ◽  
Vol 49 (4) ◽  
pp. 542-550 ◽  
Author(s):  
Gerhard Himbert ◽  
Dieter Fink

While the S-alkyl- or S-phenyl-2,3-butadienethioates 4 a-c are synthesized via the usual “Wittig ylide way”, the corresponding 2-methyl-2,3-butadienethioates 9 a-d and the 2-methyl-4.4-diphenyl-2,3-butadienethioates 9 e,f are obtained by condensation of the allenic acids 7 a,b with the thiols and thiophenols 8 in the presence of dicyclohexylcarbodiimide (DCC) and a catalytic am ount of 4-dimethylaminopyridine (DMAP). In contrast to N- or O-phenyl 2,3- butadienamides or -esters, resp., the phenyl derivatives of 4 and 9 do not undergo the intram olecular Diels-Alder reaction, but by heating, all representatives of 4 only decompose, while 9 a-d and 9 e,f rearrange to 3-alkyl(aryl)thio-2-cyclobuten-1-ones 12a-d and to 3-arylthio- 1-naphthols 14a, b, resp. Heating of the cyclobutenone 12d in the presence of N-methylaniline furnishes the 2-butenanilide 16. On reacting 1-phenylthio-1-propyne 17 with diphenylketene 18, the diphenylacetate 19 is isolated, where the naphthol derivative 14a represents the ester moiety.


2016 ◽  
Vol 52 (7) ◽  
pp. 460-466 ◽  
Author(s):  
Galyna P. Mrug ◽  
Kostyantyn M. Kondratyuk ◽  
Svitlana P. Bondarenko ◽  
Mykhaylo S. Frasinyuk

2006 ◽  
Vol 84 (10) ◽  
pp. 1487-1503 ◽  
Author(s):  
Douglas P Heller ◽  
Daniel R Goldberg ◽  
Hongqiao Wu ◽  
William D Wulff

Several derivatives of the vaulted biaryl ligand VAPOL were prepared and evaluated as chiral ligands for aluminum Lewis acids in the catalytic asymmetric Diels–Alder reactions of methyl acrylate and methacrolein with cyclopentadiene. The substituents on VAPOL were introduced into the 6- and 6′-positions in an effort to further extend the chiral pocket of the major groove, which contains the phenol functions at the 4- and 4′-positions. The set of four new ligands that have been prepared have the following groups introduced into the 6- and 6′-positions of VAPOL: bromide, methyl, phenyl and 3,5-di-t-butylphenyl. All of these ligands give lower asymmetric inductions than the unsubstituted VAPOL for the Diels–Alder reactions of both methyl acrylate and methacrolein. The positive cooperativity of added carbonyl compounds on the autoinduction in the Diels–Alder reaction of methyl acrylate and cyclopentadiene were also investigated with the VANOL and VAPOL ligands as well as the 6,6′-dibromo and 6,6′-diphenyl derivatives of VAPOL. Only the reaction with VAPOL showed any significant positive cooperativity. The reaction with VANOL was sluggish at –78 °C, but at higher temperatures, the reaction did exhibit positive cooperativity that was similar to that of VAPOL. Finally, no positive cooperativity was observed with the VAPOL ligand for the reaction of methacrolein and cyclopentadiene.Key words: Diels–Alder, asymmetric catalysis, vaulted biaryl ligands, VANOL, VAPOL.


1996 ◽  
Vol 74 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Richard Connors ◽  
Elisabeth Tran ◽  
Tony Durst

Irradiation of 2-methylbenzoyl cyanide (3a) in acetonitrile solution results in the formation of its dimer, which upon loss of HCN gives rise to the cycloadduct 7a. The dimerization also proceeds efficiently with derivatives of 3a giving adducts 7b and 7c. When 2-methylaroyl cyanides are photolyzed in the presence of a more reactive acyl cyanide the mixed adducts 8a–e are obtained in excellent yields. The cycloadducts 7a–c and 8a–e react with carbon and nitrogen nucleophiles by a tandem addition–cyclization sequence furnishing substituted naphthols (10a and 10b) and isoquinolones (11a–d), respectively. Isocoumarins 12a and 12b were prepared from the adducts 8a and 8e by treatment with potassium tert-butoxide in THF. Key words: naphthols, isoquinolones, isocoumarins, synthesis of; acyl cyanides; hetero Diels–Alder.


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