Andrzej Piasecki

Synthesis and surface properties of chemodegradable anionic surfactants: Sodium salts of sulfated 2-n-alkyl-5-hydroxymethyl-5-methyl-1,3-dioxanes

In acid-catalyzed reactions of long-chain aliphatic aldehydes (Ia-d) (a,R=n-C5H11; b,R=n-C7H15; c,R=n-C9H19; d,R=n-C11H23) with 1,1,1-tris(hydroxymethyl)-ethane (II), 2-n-alkyl-5-hydroxymethyl-5-methyl-1,3-dioxanes (IIIa-d) were obtained. Then they were reacted with SO3·pyridine complex in dry carbon tetrachloride solution, to obtain trisubstituted derivatives of 1,3-dioxane (IVa-d). They constitute a new group of chemodegradable, acetal-type anionic surfactants, which may readily hydrolyze and oxidize to nonsurfactant compounds. Physical data of the new compounds and some surface properties, such as Krafft point, critical micelle concentration (CMC), surface tension of aqueous solution near CMC (γCMC) and wetting and foaming properties, were determined. Sodium salts of sulfated 2-n-alkyl-5-hydroxymethyl-5-methyl-1,3-dioxanes (IVa-d) exhibit aqueous solution properties similar to those of the well-known sodium alkyloligooxyethylene sulfates. Presence of the 5-methyl-1,3-dioxane moiety in molecules of compounds IVa-d introduces hydrophobic character comparable to the effect of three oxyethylene groups (-CH2CH2O-) or of two methylene groups (-CH2-) of the alkyl chain in sodium alkyl ether sulfates [R(OCH2CH2)mOSO3Na] with equal R value.

Synthesis and surface properties of oxyethylenated 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes

In acid-catalyzed reactions of long chain aliphatic aldehydes (I) (R=n−C7H15; n−C9H19; n−C11H23) with 1,1,1-tris(hydroxymethyl)propane (II), 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes (III) were obtained. The latter were then reacted with ethylene oxide in the presence of sodium methoxide.Three series of oxyethylenated cyclic acetal derivatives (IV) were obtained. They constitute a new group of chemodegradable surfactants which readily hydrolyze and oxidize in natural water reservoirs. Physical data of the new compounds and some surface properties such as cloud points (Cp), critical micelle concentrations (cmc), changes of free energy of micellization, (ΔG°cmc), surface tensions of aqueous solutions near cmc, γmin, and wetting and foaming properties, were determined. The surfactants (IV) have aqueous solution properties similar to those of oxyethylenated longchain aliphatic alcohols. It is shown that the micellization of surfactants (IV), expressed in terms of ΔG°cmc, depends both on the length of the aliphatic chain at the C-2 carbon atom and on the presence of ethyl group at C-5 of 1,3-dioxane ring which enhances the hydrophobic character of derivatives (III). Hence, the surfactants have a higher surface activity than oxyethylenated 2-alkyl-4-hydroxymethyl-1,3-dioxolanes or 2-alkyl-5,5-bis-(hydroxymethyl)-1,3-dioxanes. The use of 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes (III) in surfactant synthesis is an example of applying hydrophobic intermediates obtained from aldehydes only. This, and the chemodegradability mentioned make the compounds a very interesting group of new surfactants.

An Efficient Method for the Preparation of Pure Long-Chain CIS-and Trans-2-n-Alkyl-5-Hydroxy-1,3-Dioxanes #

Abstract The title compounds were obtained with high yields from four-component mixtures of glycerol acetals by combining the transacetalization reaction with the crystallization process followed by fractional distillation. Part XXII in the series: Acetals and Ethers. For Part XXI see Ref. 1

Alkoxyalkyl-substituted glycerol acetals: New hydrophobic intermediates for surfactant synthesis

In acid-catalyzed, one-step reactions of monofunctional alcohol (I) and glycerol mixture with a simple α,β-unsaturated carbonyl compound (acrolein, crotonaldehyde or methylvinyl ketone), four component glycerol acetals [mixtures ofcis-+trans-2-(2-alkoxyalkyl)-substituted derivatives of 4-hydroxymethyl-1,3-dioxolanes and 5-hydroxy-1,3-dioxanes] or two component glycerol ketals [mixtures ofcis-+trans-2-(2-alkoxyethyl)-2-methyl-4-hydroxymethyl-1,3-dioxolanes] were obtained, respectively. These compounds may be used as a new group of hydrophobic intermediates for synthesis of chemodegradable surfactants, which rapidly hydrolyze to nonsurfactant compounds in acidic aqueous solutions. Methods of synthesis, yields, compositions and chemical structures of components of reaction products, and products of their chemical degradation have been discussed.

Acetals and ethers-xiii Reaction products of 2-butenal with ethylene glycol☆

Abstract The unsaturated cyclic acetal, 2-(1-propenyl)-1,3-dioxolane (2), has been found as an intermediate product in the p-toluenesulfonic acid catalysed reaction of 2-butenal with an excess of ethylene glycol. The final product consisted of 2-[2-(2-hydroxyethoxy)-propyl]-1,3-dioxolane (3), and a small amount of geometric isomers of cis- and trans-5-(2-hydroxyethoxy)-7-methyl-1,4-dioxepane (4a and 4b, respectively).

Acetals and ethers. XV. Reactivity of mono- and disubstituted cyclic acetals toward ozone in aqueous solution

Mono- and disubstituted derivatives of 1,3-dioxolane and 1,3-dioxane were oxidized by ozone in aqueous solutions containing monosodium carbonate. In both alkylsubstituted 1,3-dioxacyclane series the rates of oxidation increase with increasing length of alkyl substituents at the C-2 dioxacyclane carbon atom. However, the alkyl derivatives of 1,3-dioxane (III, IV, V) are more resistant toward ozone than the respective 1,3-dioxolane derivatives (I, II). The pseudo-first order rate constants for the oxidation of glycerol acetals (VIIa–VIId) decrease in the order:cis-dioxolane>trans-dioxolane>cis-dioxane>trans-dioxane.

Preparation of Diastereometrically Pure Sodium Salts of Sulfated 2-n-Alkyl-5-Hydroxymethyl-5-Methyl-1,3—Dioxanes

Abstract Sulfur trioxide pyridine complex has been found to be an excellent reagent for preparation of dia-stereometrically pure sodium salts of sulfated cis- and trans-2-n-alkyl-5-hydroxymethyl-5-methyl-1,3-dioxanes.

Amphiphilic amine-N-oxides with aliphatic alkyl chain act as efficient superoxide dismutase mimics, antioxidants and lipid peroxidation blockers in yeast.

Amphiphilic 3-(alkanoylamino)propyldimethylamine-N-oxides with different length of the alkyl chain,i.e. different hydrophilic-lipophilic balance, act in micromolar concentrations as SOD mimics by lifting the inhibition of aerobic growth caused by SOD deletions inSaccharomyces cerevisiae. They also enhance the survival ofsod mutants ofS. cerevisiae exposed to the hydrophilic superoxide-generating prooxidant paraquat and the amphiphilic hydroperoxide-producingtert-butylhydroperoxide (TBHP), and largely prevent TBHP-induced peroxidation of isolated yeast plasma membrane lipids. Unlike the SOD-mimicking effect, the magnitude of these effects depends on the alkyl chain length of the amine-N-oxides, which incorporate intoS. cerevisiae membranes, causing fluidity changes in both the hydrophilic surface part of the membrane and the membrane lipid matrix. Unlike wild-type strains, the membranes ofsod mutants were found to contain polyunsaturated fatty acids; the sensitivity of the mutants to lipophilic pro-oxidants was found to increase with increasing content of these acids.sod mutants are useful in assessing pro- and antioxidant properties of different compounds.

Acetals and ethers, XVII. One- or two-step syntheses of 2-(2-alkoxyethyl)-1,3-dioxacyclanes

Abstract2-(2-Alkoxyethyl)-1,3-dioxanes (1) were prepared by ap-toluenesulfonic acid-catalyzed, one-step reaction of propenal with a mixture of aliphatic alcohol and trimethylene glycol in good yields. The transacetalization reaction of 1,1,3-trialkoxypropanes (3) with ethylene glycol or propylene-(1,2)glycol afforded good yields of pure 2-(2-alkoxyethyl)-1,3-dioxolanes (5 or6), respectively. This reaction proceeds through an intermediate 1,3-dialkoxy-1-(2-hydroxyalkoxy)-propane.ZusammenfassungIn der durchp-Toluolsulfonsäure — katalysierten, direkten Reaktion von Propenal mit einem Gemisch von aliphatischem Alkohol und Trimethylenglykol wurden die entsprechenden 2-(2-Alkoxyethyl)-1,3-dioxane (1) in guten Ausbeuten erhalten. Die Umacetalisierung von 1,1,3-Trialkoxypropanen (3) mit Ethylenglykol oder 1,2-Propylenglykol lieferte 2-(2-Alkoxyethyl)-1,3-dioxolane (5 oder6) in guten Ausbeuten. Die Umacetalisierungsreaktion von 1,1,3-Trialkoxypropanen verläuft über 1,3-Dialkoxy-1-(2-hydroxyalkoxy)-propane als Zwischenprodukte.

Assaying the antioxidant and radical scavenging properties of aliphatic mono- and di-N-oxides in superoxide dismutase-deficient yeast and in a chemiluminescence test.

The antioxidative action of amphiphilic mono-(alkanoylamino) ethyldimethylamine-N-oxides (EDA), di-N-oxides 1,1-bis{[2-(N,N-dimethylamino)ethyl]amido}alkane-di-N-oxides (MEDA) and 1,1-bis {[3-(N,N-dimethylamino)propyl]amido}alkane-di-N-oxides (MPDA) with a 12- and 14-membered acyl chain againsttert-butylhydroperoxide (TBHP)-produced peroxyl and paraquat (PQ)-generated superoxide radicals was determined in superoxide dismutase-deficient mutants ofSaccharomyces cerevisiae, and, in parallel, in a chemical assay based on chemiluminescence changes caused in a luminol system by peroxyl radicals generated from the azo-compound 2,2′-azobis(2-amidinopropane dihydrochloride) (AAPH). At 30 µmol/L, the shorter-chain compounds did not affect strain survival while longer-chain ones, in some cases, lowered the survival ofsod2 andsod1 sod2 cells. Whether nontoxic or medium-toxic, allN-oxides protected thesod strains against the toxic effect of PQ and TBHP, the protection being stronger with the di-N-oxides. The survival was lowered only by 14-MPDA in the TBHP-exposedsod2 mutant. Membrane lipids isolated from all strains were protected against TBHP-induced peroxidation by both mono- and di-N-oxides, the protection being dependent on the alkyl chain length. Mono-N-oxides were again less active than di-N-oxides with the same alkyl chains, the antiperoxidative activity being also dependent on lipids isolated from the individual mutants. In the chemiluminescence assay, the IC50 value of theN-oxides for scavenging of radicals generated from AAPH generally decreased (i.e. the scavenging efficiency increased) with increasing chain length and was the highest in MEDA.