136106-29-1Relevant academic research and scientific papers
Reactions of Ethoxycarbonylmethylene(triphenyl)phosphorane with some ortho-Quinones in the Presence of Triphenylphosphine, Alcohols and Acetic Anhydride
Nicolaides, Demetrios N.,Adamopoulos, Spyros G.,Lefkaditis, Demetrios A.,Litinas, Konstantinos E.,Tarantili, Petroula V.
, p. 283 - 290 (2007/10/02)
The reactions of ortho-quinones 1a, 1c and 1d with ylide 2 in the presence of triphenylphosphine afforded the ylides 11a, 11c and 11d and compound 12.The reactions of 1a and 1c with 2 in refluxing methanol or ethanol gave compounds 16 and 17 respectively, while the reactions of 1a-d with 2 in acetic anhydride yielded the acetates 18a, 18b, 18d and 19b, 19d, the furan derivative 24 and the ylide 25.Compounds 8 and 9 were also obtained in most of the above reactions.Wittig reactions of the ylides 11a, 11c with p-nitrobenzaldehyde and of ylide 2 with coumarins 8a and 29 resulted in compounds 14a, 14c, 26 and 30 respectively.The transformations of compounds 18, 19 into 8, 9 as well as of compound 26 into 28 were also studied.
REACTION OF PHOSPHONIUM YLIDES WITH 3,5-DI-TERT-BUTYL-1,2-BENZOQUINONE
Abdou, Wafaa M.,Ganoub, Neven A. F.,Abdel-Rahman, Naglaa M.
, p. 91 - 96 (2007/10/02)
The reactions of quinone 1 with several Wittig reagents have been studied.When 1 was added to excess of 2, the corresponding 1,1,2,2-tetrabromocyclobutene derivative 4 was obtained.Reaction of 1 with moderate-stabilized ylides 5a,b at room temperature afforded the monosubstituted α,β-unsaturated esters 6, while carrying out the reaction in boiling benzene led to the formation of coumarin-derivatives 8.On the contrary, the reaction of 1 with resonance-stabilized ylides 5c,d takes place, only at higher temperatures to give disubstituted α,β-unsaturated ketones 9.Key words: 3,5-Di-tert-butyl-1,2-benzoquinone; o-quinones; ylide-phosphoranes.
Reactions of ortho-Quinones with Ethoxycarbonylmethylene(triphenyl)phosphorane. Trapping of the ortho-Quinone Methanide Intermediates
Nicolaides, Demetrios N.,Adamopoulos, Spyros G.,Lefkaditis, Demetrios A.,Litinas, Konstantinos E.
, p. 2127 - 2132 (2007/10/02)
The reactions of the ortho-quinones (5a-d) with the phosphorus ylide (6) afforded, besides the expected coumarin derivatives (10a-d), compounds (9d), (11b and c), (13), and (14).When the reactions between compounds (5a-d) and (6) were carried out in the presence of ethyl vinyl ether (20) the pyran derivatives (21a, b, and d) and (22a, b, and d) were obtained as main products, by a trapping process of the ortho-quinone methanide intermediates (7a, b, and d) with the dienophile (20).Similarly, the reaction between compounds (5a) and (6) in the presence of α-methylstyrene afforded mainly the pyrans (23I and II).Compounds (16), (19), and (24) were also prepared and studied.
