54874-23-6Relevant academic research and scientific papers
β,β-dimethylacrylophenones : BF3.ET2O-POCl3 catalysed acylation of phenols using β, β-dimethylacrylic acid
Jain, Niveta,Krishnamurty
, p. 1237 - 1241 (2007/10/03)
Boron trifluoride etherate - phosphoryl chloride reagent is a useful reagent for the condensation between phenols and β,β-dimethylacrylic acid. The main products are acrylophenones. But surprisingly hydroquinone gives mono and diacrylates.
ON THE REACTION OF SUBSTITUTED PHENOLS AND 3-METHYLBUT-2-ENOIC ACID. A COMPARATIVE STUDY
Seboek, Peter,Jekoe, Jozsef,Timar, Tibor,Jaszberenyi, Joseph Cs.
, p. 2099 - 2114 (2007/10/02)
A systematic and comparative study of the reaction of a series of substituted phenols and 3-methylbut-2-enoic acid in zinc chloride/phosphorus oxychloride and aluminum chloride/phosphorus oxychloride reveals that the formation of phenolic esters and 2,2-dimethyl-4-chromanones is strongly influenced by the substituents, their popsition on the aromatic ring of the starting phenols.Based on our study, a mixed Friedel-Crafts and Fries rearrangement mechanism is in operation in these reactions.
On the synthesis of substituted 2,2-dimethyl1-4-chromanones and related compounds
Seboek, Peter,Jekoe, Jozsef,Timar, Tibor,Jaszberenyi, Joseph Cs.
, p. 2791 - 2794 (2007/10/02)
A systematic study of the reaction of a series of monosubstituted phenols 3 and 3-methylbut-2-enoic acid 4 in phosphorus oxychloride/zinc chloride revealed that the formation of 4-chromanones was strongly infuenced by the substituents and their position on the aromatic ring of the starting phenols.
Studies of Chromenes. Part 6. 3-Hydroxymethyl- and 3-Formylprecocenes: Potential Precursors of Other 3-Substituted Precocenes.
Brown, Philip E.,Islam, Qamrul
, p. 1634 - 1651 (2007/10/02)
3-Hydroxymethylene-7- (and -6,7-di)methoxy-2,2-dimethylchroman-4-ones are reduced to diols from which 3-hydroxymethylchromenes may be obtained.Sodium borohydride reduction of the corresponding 3-chloromethylenechromanones, themselves readily prepared by the action of thionyl chloride on the hydroxymethylene derivatives, gives the 3-formylchromenes.Both chromene derivatives offer access to a range of 3-substituted precocenes.
STUDIES ON THE SYNTHESIS OF PRECOCENES. THE PHOTO-FRIES REARRANGEMENT OF ESTERS OF α,β-UNSATURATED CARBOXYLIC ACIDS AND META-OXYGENATED PHENOLS
Miranda, Miguel A.,Primo, Jaime,Tormos, Rosa
, p. 673 - 682 (2007/10/02)
The photo-Fries rearrangement of a series of aryl esters of α,β-unsaturated carboxylic acids 1a,b and 2 has been investigated, in order to explore the possibilities of this reaction as a key step in the synthesis of precocenes and related compounds.In all cases, the photolysis in hexane does not lead to any observable transformation, but in the presence of potassium carbonate takes place a migration of the acyl group to the two ortho-positions.Additionally, trans-cis photoisomerization occurs with the trans-butenoate 1b.The resulting o-hydroxyketones 4a, 4b, 4c, 5a, 5b, 5c, and 8 are easily and efficiently cyclized to the corresponding 4-chromanones 6a, 6b, 7a, 7b, and 9.A second photo-rearrangement is observed in the case of 9, although the yield is low, due to deactivation by the carbonyl group.Cyclization of 10 gives rise to the tricyclic dichromanone 11.Compounds 6a and 11 are reduced and subsequently dehydrated by known procedures to afford the active chromenes 3 and 12.
Studies of Chromens. Part 2. Synthesis of 7-Methoxy-2,2-dimetylchromen-3-carboxylic acid
Anastasis, Panayiotis,Brown, Philip E.
, p. 197 - 200 (2007/10/02)
The preparation of the title compound (1a) is described.Effects of C-2 methyl groups on ring opening and alkylation of chroman-4-ones under basic conditions are discussed.The reaction of hydrazine with 3-ethoxycarbonyl-7-methoxy-2,2-dimethylchromen (1d) a
