Compound polyfunctional

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cycHc, the name is formed using carbaldehyde to indicate the functionaUty. The lUPAC system of aldehyde nomenclature drops the final e from the name of the parent acycHc hydrocarbon and adds al If two aldehyde functional groups are present, the suffix -dialis used. The prefix formjlis used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

Dicyclopentadienedicarboxyhc acid can undergo a Diels-Alder reaction in the presence of a stoichiometric amount of a dienophile at 140—190°C to give an adduct of the monomeric acid. The yield of adduct is usually 75—95%. A large number of polyfunctional compounds are easily prepared in this manner. The reaction with maleic anhydride gives a tribasic acid. 

Mention may also be made here of a number of polyfunctional compounds such as allyl methacrylate and glycol dimethacrylates which have been used to produce a cross-linked sheet of enhanced heat resistance compared with conventional poly(methyl methacrylate). Some manufacturers supply the sheet in an incompletely cross-linked state which allows a limited amount of forming after which the sheet may be further heated to complete the cure. 

The reactions of olefins with peracids to form epoxides allows for the selective oxidation of carbon-carbon double bonds in the presence of other functional groups which may be subject to oxidation (for example, hydroxyl groups). The epoxides that result are easily cleaved by strong acids to diols or half-esters of diols and are therefore useful intermediates in the synthesis of polyfunctional compounds. 

When compounds contain more than one functional group in their structures, they are referred to as polyfunctional compounds. Examples include... 

The reaction of bromotrichloromethane with alkenylcyclopropanes (ref. 15) is of interest from the synthesis of polyfunctional compounds standpoint. 

The rapid oxidations of certain of these polyfunctional compounds by alkaline permanganate were examined as a supplement to the study of acetone oxidation (p. 314). The oxidations of acetol and pyruvaldehyde show identical rate laws of the form... 

The reactivity of these oxidants towards organic substrates depends in a rough manner upon their redox potentials. Ag(II) and Co(III) attack unactivated and only slightly activated C-H bonds in cyclohexane, toluene and benzene and Ce(IV) perchlorate attacks saturated alcohols much faster than do Ce(lV) sulphate, V(V) or Mn(III). The last three are sluggish in action towards all but the active C-H and C-C bonds in polyfunctional compounds such as glycols and hydroxy-acids. They are, however, more reactive towards ketones than the two-equivalent reagents Cr(VI) and Mn(VIII) and in some cases oxidise them at a rate exceeding that of enolisation. 

Nonlinear addition polymers are readily obtained by copolymerizing a divinyl compound (e.g., divinylbenzene) with the vinyl monomer (e.g., styrene), as already mentioned. Products so obtained exhibit the insolubility and other characteristics of space-network structures and are entirely analogous structurally to the space-network polymers produced by the condensation of polyfunctional compounds. Owing to... 

Docherty, G., Jones, V. and Evershed, R. P. (2001) Practical and theoretical considerations in the gas chromatography/combustion/isotope ratio mass spectrometry 813C analysis of small polyfunctional compounds. Rapid Communications in Mass Spectrometry 15, 730 738. 

An example of an exclusive chemoselective reduction of a benzylic hydroxy function in a polyfunctional compound is seen in the conversion of 23 into 24... 

Triethylsilane/boron trifluoride etherate in chloroform at room temperature reduces only the benzylic 12-hydroxy group of the polyfunctional compound 36 to form ( )-homochelidonine 37 in 92% yield (Eq. 44).138... 

The combination of boron trifluoride etherate and triethylsilane can cause the reduction of tertiary fluoride centers even in polyfunctional compounds (Eq. 55).194... 

These reaction conditions also permit the chemoselective quantitative reduction of benzaldehyde to benzyl alcohol without any concomitant reduction of either acetophenone or 3,3-dimethylbutan-2-one present in the same reaction mixture.83 Additionally, this useful method permits the reduction of aldehyde functions in polyfunctional compounds without affecting amide, anhydride, eth-ylenic, bromo, chloro, or nitro groups.79,80,319... 

The multidipole interaction in a bimolecular reaction arises if one or both reactants contain several polar groups [31]. The multidipole effect shows itself as a deviation of the rate constant for the addition of a polar radical to a polyfunctional compound (calculated in... 

First, all these classes of compounds are 1,3-dipoles, that is, they serve as the starting reagents in 1,3-dipolar cycloaddition reactions, which can be considered as a modem powerful method for the synthesis of various heterocyclic and polyfunctional compounds (5). All three dipoles have the common reactive fragment ... 

The reactions of the resulting stabilized ions 153a,b with silicon dioxide produces isolable polyfunctional compounds 155a,b. It should be emphasized that the configuration of the stereocenters in nitronate (153) remains unchanged in the course of the transformation and the reaction is stereoselective with respect to the new stereocenter at the atom bearing the nitro group. 

This process was carried out with the use of diastereomerically and enan-tiomerically pure five-membered cyclic nitronates (213). After selective silylation of the hydroxy group and intramolecular cycloaddition, these compounds give enantiomerically pure fused systems, which are similar precursors of enantiomer-ically pure hydroxyamino acids and other polyfunctional compounds possessing potential biological activity. 

Reactions of Cyclic Conjugated Ene Nitroso Acetals with Nucleophiles The reaction of six-membered cyclic ene nitroso acetals (475) with nucleophiles has a high potential and will probably provide the basis for a promising procedure for the synthesis of polyfunctional compounds from very simple precursors, the more so that the configurations of stereocenters in the starting nitronate (475) can be retained in particular transformations (Scheme 3.253). Unfortunately, the available data (264) are insufficient to elucidate the complete mechanism of this process. 

It is very significant that most of these polyfunctional compounds have also been identified in ambient aerosols (Tables 3-2 and 3-3) and... 

The complex hydride reductions of nitriles to aldehydes compare favorably with the classical Stephen reduction which consists of treatment of a nitrile with anhydrous stannous chloride and gaseous hydrogen chloride in ether or diethylene glycol and applies to both aliphatic and aromatic nitriles [183,285, 1152]. An advantage of the Stephen method is its applicability to polyfunctional compounds containing reducible groups such as carbonyl that is reduced by hydrides but not by stannous chloride [1153]. 

FIGURE 5. Different types of chelation in Li+ cation complexation (a) tme chelation in a polyfunctional compound (e.g. CH30CH2CH20H-Li+, 2) (b) formation of nonclassical chelates involving fluorine or chlorine atoms (e.g. (CF3)2CHOH—Li+, 3) (c) unexpected chelate structures (e.g. PhOCH3-Li+, 4). Reproduced with permission from Ref 34... 

Condensation polymerizations (polycondensations) are stepwise reactions between bifunctional or polyfunctional components, with elimination of small molecules such as water, alcohol, or hydrogen and the formation of macromo-lecular substances. For the preparation of linear condensation polymers from bifunctional compounds (the same considerations apply to polyfunctional compounds which then lead to branched, hyperbranched, or crosslinked condensation polymers) there are basically two possibilities. One either starts from a monomer which has two unlike groups suitable for polycondensation (AB type), or one starts from two different monomers, each possessing a pair of identical reactive groups that can react with each other (AABB type). An example of the AB type is the polycondensation of hydroxycarboxylic acids ... 

Two further rules are needed to name polyfunctional compounds ... 

The present authors studied the extraction of aromatic amines into ILs. As is seen from experimental data for [C4CiIm][PFg] (Figure 9.2), aniline, napthylamine, and o-toluidine are efficiently extracted from the alkaline aqueous solution. Thus, as in the case of phenols, neutral (molecular) forms of solutes were extracted. Another example of the same behavior is given by many polyfunctional compounds, for example, 8-hydroxyquinoline (Figure 9.3 presents a comparison of extraction pH-profile with the distribution diagram for ionic forms of the solute). 

In certain polyfunctional compounds, an aldehyde or ketone group can also be named as a substituent on a molecule with another functional group as its root. The aldehyde carbonyl is given the prefix formyl-, and the ketone group is named 0x0- with a number to show its position in the molecule. Compounds with both an aldehyde and ketone are named as aldehydes, because aldehydes have functional group priority over ketones. A ketone containing a benzene ring is named as a -phenone. 

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