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Diphenylpropanes

Among the plant phenols, the flavonoids and the anthocyanidins, belonging to the 1,3-diphenylpropans, have been studied in most detail, mainly because of their potential health benefits. With more than 4,000 different flavonoids known, systematic studies of the effects of variation in molecular structure on physico-chemical properties of importance for antioxidative effects have also been possible (Jovanovic et al, 1994 Seeram and Nair, 2002). Flavonoids were originally found not to behave as efficiently as the classic phenolic antioxidants like a-tocopherol and synthetic phenolic antioxidants in donating... [Pg.320]

Prevalence of the head-to-tail arrangement in vinyl polymers is abundantly confirmed by determinations of polymer structures. Staudinger and Steinhofer found that destructive distillation of polystyrene at about 300° yielded 1,3-diphenylpropane, 1,3,5-triphenyl-pentane, and 1,3,5-triphenylbenzene... [Pg.233]

FIGURE 4.45 Cytochrome P450-catalyzed hydroxylation of p-mono-substituted 1,3-diphenylpropanes. [Pg.71]

Ueno and Okawara (184) were the first to explicitly formulate a conjugated thiocarbonyl ylide as an intermediate in the reaction of l,3-dithiolane-2-thione with 4-bromophenacyl bromide. The initially formed thiocarbonyl ylide undergoes deprotonation with sodium hydride to give 2-(4-bromophenyl)-l-oxa-4,6,9-trithias-piro[4.4]non-2-ene. 1,3-Diacylated thiocarbonyl ylides of type 149 (Scheme 5.45) have also been proposed as intermediates in the reaction of 1,3-diphenylpropane-1,3-dione with thionyl chloride. This reaction leads to 2,2,4-tribenzoyl-5-phenyl-... [Pg.346]

Note Due to the rapid decomposition of methanesulfonyloxy-1,3-diphenylpropane-l,3-diol, it is important to store the material at 0 °C. [Pg.91]

The flavonoids, the derivatives of 1,3-diphenylpropane, are a large group of natural products, which are widespread in higher plants hut also found in some lower plants, including algae. Most flavonoids are yellow compounds, and contrihute to the yellow colour of the flowers and fruits, where they are usually present as glycosides. [Pg.365]

The reaction can also be base-catalyzed, in which case there is nucleophilic addition and a carbanion mechanism.418 Carbanions most often used are those stabilized by one or more u-aryl groups. For example, toluene adds to styrene in the presence of sodium to give 1,3-diphenylpropane 419... [Pg.791]

In addition, high ortho regioselectivity (32%) was observed for bibenzyl, whereas biphenyl, diphenylmethane and 1,3-diphenylpropane exhibited the usual high para regioselectivity (100%, 98%, and 95%, respectively).95... [Pg.414]

Separation of two aromatic ring systems by a three-atom link, as in 1,3-diphenylpropane, is associated with a propensity for excimer formation, since the possible interplanar spacing of about 3.5 A between overlapping... [Pg.148]

By utilizing the above methods, a convenient route to the tetracyclic ketone 240, a derivative of the benzobicyclo[3.2.1]octane skeleton, has been developed847 using 2,-methoxy-5,-methyl-1,3-diphenylpropane 239 (Scheme 5.85). [Pg.721]

Aryl acetones react with the Vilsmeier-Haack reagent to form conjugated iminium salts 726, which spontaneously cyclize upon basic aqueous work-up to afford 3-formyl-pyran-4-ones (Scheme 180) <2004T5069>. (1,3-Diphenylpropane-2,2-diyl)bis(butylsulfane) 727 also reacts with the Vilsmeier-Haack reagent to afford 3,5-diphenyl-4//-pyran-4-one upon basic aqueous workup (Equation 291) <2004T5069>. [Pg.573]

Significant characteristics of the porphyrin iron monoxide are seen in the chemical reactivity. Naphthalene is converted initially to the corresponding arene oxide on treatment with P 450 (19), consistent with a molecular mechanism of oxygen transfer from an iron monoxide to the aromatic nucleus. Retention of stereochemistry in the P-450 catalyzed hydroxylation of d ethylbenzene also supports the molecular mechanism. The unusually large kinetic isotope effect observed for the P-450 oxidation of dideutero 1,3-diphenylpropane, kJkD = 11, demonstrates that C—H cleavage is involved in the rate determining step (20), probably in a very unusual environment, not incompatible with a molecular mechanism. [Pg.296]

Radical 3-Bond Scission. Model studies clearly show that certain bonds, such as the (-CH2-CH2-) bond in 1,3-diphenylpropane (15), are rapidly cleaved even though these bonds are too strong to undergo substantial bond homolysis under reaction conditions (Table III). An alternative route for bond breaking is through a chain reaction sequence involving 3-bond scission, as follows ... [Pg.105]

Reaction of the arene ruthenium precursor 200 with polystyrene and hydrogen leads to the loss of both cycloolefins and gives a polymeric ruthenium complex, used for catalytic hydrogenation, for which EXAFS indicated a Ru—C distance of 2.05 A. A similar reaction of derivative 200 with 1,3-diphenylpropane gives complex 203 and a compound of composition (diphenylpropane)Ru2 (204) (129,130) [Eq. (18)]. [Pg.203]


See other pages where Diphenylpropanes is mentioned: [Pg.823]    [Pg.824]    [Pg.1018]    [Pg.323]    [Pg.71]    [Pg.24]    [Pg.92]    [Pg.4]    [Pg.4]    [Pg.57]    [Pg.187]    [Pg.187]    [Pg.217]    [Pg.330]    [Pg.89]    [Pg.366]    [Pg.83]    [Pg.36]    [Pg.630]    [Pg.93]    [Pg.225]    [Pg.171]    [Pg.171]    [Pg.272]    [Pg.21]    [Pg.26]    [Pg.30]    [Pg.94]    [Pg.728]    [Pg.729]    [Pg.731]    [Pg.735]   
See also in sourсe #XX -- [ Pg.21 , Pg.24 ]




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1,2-Diphenylpropane derivatives

1,3-diphenylpropane

1,3-diphenylpropane

1- Bromo-l,2-diphenylpropane

1.2- Diphenylpropane, preparation

2 Methyl 1,1-diphenylpropane

Diphenylpropan

Diphenylpropan-2-one

Diphenylpropan-l-one

Diphenylpropane-l,3-dione

Trans-1,3-Diphenylpropane

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