Diels-Adler adducts

To address this problem water-insoluble latex copolymers containing the covalently bounded dye /V-(2,4-dinitropheny I)-1,4-pheny lene-diamine have been prepared. When printed as ink jet ink, latex particulates formed a hydrophobic print film on the media surface, thereby entrapping and protecting the colorant within the film. The process for preparing these agents consisted of initially forming the Diels-Adler adduct with furan and maleimide followed by a transimidation with 3-amino-1-propanol. 

Pyrolysis of o-hydroxybenzyl alcohol at 550 °C resulted in the formation of simple o-quinone methide, which was directly observed using low-temperature IR spectroscopy.122 Pyrolysis of chroman (Scheme 33) at 400-600 °C gives the simple o-quinone methide and ethene along with o-cresol, benzofuran, and styrene.123,124 The o-quinone methide was trapped with alkenes to form Diels Adler adducts, with hydrogen gas or hydrogen atom to form o-cresol, or underwent a further pyrolysis to CO and fulvene. 

Two examples of diene addition products have been claimed in the literature. Structures 141 and 142 were considered for a 1 1 adduct of anthranil and maleic anhydride, and since 3-phenylanthranil did not react analogously, structure 141 was preferred.271 Also, anthranil and jV-phenylmaleimide have been reported to give compound 143, which with alkali is hydrolyzed and dehydrated to give acridinic acid.272 Attempts to form Diels-Adler adducts between 3-benzoylanthranil and maleic anhydride or n-butyl vinyl ether met with no success.165... 

Patent Diels-Adler Adducts of Epoxybutene and Epoxybutene Derivatives... 

The skewed reagent ratios are based on an earlier observation (2) that higher yields of Diels-Adler adducts were obtained when the diene/ene reagent ratio consistently kept low during the course of the reaction. 

Cjs-hydroxylation of 3,6-dihydro-2-methoxy-2H-pyran (341) afforded " a mixture of methyl 2-deoxy-a- and (3-DL-etyfAro-pentopyranosides (342). Hydrolysis of this mixture gave free 2-deoxy-DL-eo op ntos (2-deoxyribose). Compound 341 was obtained by the reductive removal of the p-toluenesul-fonyloxy group in methyl 3,4-dideoxy-2-0-p-toluenesulfonyl-a,p-DL-pent-3-eno-pyranoside (345). Mochalin °° obtained 341 in three steps starting from the Diels-Adler adduct 343 via the amide 344 and its Hoffman degradation in methanol solution. 

C) in the gas phase in a constant volume reactor, determine whether or not the data are consistent with a rate expression of the form r=kCpC and the value of the rate constant. Initially, the reaction mixture contains equal molar quantities of species A and B, together with an unknown concentration of an inert species (i.e., the quantity of the Diels-Adler adduct, which forms as the gas mixture is heated to 300°C). 

Other results with unsaturated thioamides include a nice reversal [233] of the endo selectivity in favour of the exo adduct by adjustment (Table 4, entry 9) of the thermal conditions (-30 °C vs 80 °C). Unexpected dimerisa-tions of enethioamides (entries 10 and 11) were observed [234, 235]. Thiocarbonyl chemistry has already been used in fullerene chemistry Acyl thio-acrylamides react [236] with [60]fullerene to yield hetero-Diels-Adler products (Table 4, entry 12). 

For example, the mesoionic 1,3-dithiolones (2) combine across the 2,5-position at 90-130 °C with symmetrically substituted alkynes as dipolarophiles with formation of non-isolable primary adducts of type (85). The latter fragment in a retro Diels-Adler type... 

Figure 19 summarizes the work of Harper, who took the Diels and Adler adduct of dichlorovinylene carbonate with... 

An isotope effect on the rate of the Diels-Adler reactiop between cyclopentadiene and maleic-dj anhydride was observed by Van Sickle (105). In methylene chloride at 0°C., under conditions of kinetic control, he obtained AA = —34 cal. for formation of the endo adduct. If both bonds are being formed simultaneously, the acceleration is indeed small, and could be taken as evidence that the transition state is reactant-like. However, if one accepts the Woodward and Katz (106) mechanism, the isotope effect refers to bond formation at only one center and — AAF / is twice as large. 

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