Based triols

Petrovic ZS, Cvetkovic I, Hong DP, Wan X, Zhang W, Abraham TW, Malsam J (2009) Vegetable oil-based triols from hydroformylated fatty acids and polyurethane elastomers. Eur J Lipid Sci Technol 112 97-102. doi 10.1002/ejlt.200900087... 

IPDI-based prepolymer. This is an aliphatic prepolymer formed by the reaction of IPDI with polyether polyol (3000 molecular weight PPO-based triol) (PPG = polypropylene oxide). The NCO group content of such systems is about 3.4%, and the viscosity about 15 000 CP at 20°C. Solid content is typically 98%-100%. The general reaction is given in Figure 2.22. This prepolymer may typically be used in two-part elastomer systems. 

The most important polyether triol, PO homopolymer, is the glycerine based triol of MW of 3000 daltons, used in continuous slabstock PU foams (Figure 4.15). 

Table 13.3 The characteristics of some glycerol-based triols for rigid PU foams ...

The principal components of commercially available urethane coatings are di- or polyisocyanates and di- or polyhydroxy compounds. Active hydrogen-containing compounds, especially diols and diamines, as well as alkanolaraines, are also employed as chain extenders. In addition, various cross-linking agents such as neutral or tertiary amine based triols or tetrols are also used. 

The liquid feedstock consists of an extended diisocyanate prepolymer and a caprolactone-based triol. The feed enters the reactor at 318 K with an initial reactive group concentration of 2.64 X lO g-equiv/m. The feed flow rate is 1.05 m / min. What reactor volumes are required in each case At what rate must thermal energy be removed to keep the system isothermal What is the effluent temperature when the reactor operates adiabatically ... 

Nomenclature is based on the keto-enol tautomers. The trihydroxy form is variously designated cyanuric acid, j -triaziae-2,4,6-triol or 2,4,6-trihydroxy-j -triaziQe. The trioxo stmcture, or j -triaziae-2,4,6(lJT,3JT,5JT)-trione is the basis for the isocyanuric acid nomenclature. 

The general features of the monensin synthesis conducted by Kishi et al. are outlined, in retrosynthetic format, in Scheme 1. It was decided to delay the construction of monensin s spiroketal substructure, the l,6-dioxaspiro[4.5]decane framework, to a very late stage in the synthesis (see Scheme 1). It seemed reasonable to expect that exposure of the keto triol resulting from the hydrogen-olysis of the C-5 benzyl ether in 2 to an acidic medium could, under equilibrating conditions, result in the formation of the spiroketal in 1. This proposition was based on the reasonable assumption that the configuration of the spiroketal carbon (C-9) in monensin corresponds to the thermodynamically most stable form, as is the case for most spiroketal-containing natural products.19 Spiro-ketals found in nature usually adopt conformations in which steric effects are minimized and anomeric effects are maximized. 

It is appropriate at this juncture to address some of the more useful transformations of 2,3-epoxy alcohols.913 A 2,3-epoxy alcohol such as compound 14 possesses two obvious electrophilic sites one at C-2, and the other at C-3. But in addition, C-l of a 2,3-epoxy alcohol also has latent electrophilic reactivity. For example, exposure of 14 to aqueous sodium hydroxide solution results in the formation of triol 19 in 79% yield (see Scheme 5). In this interesting transformation, hydroxide ion induces the establishment of an equilibrium between 2,3-epoxy-l-ol 14 and the isomeric 1,2-epoxy-3-ol 18. This reversible, base-induced epoxide migration reaction is a process known as the Payne rearrangement.14... 

Storey RF and Hickey TP. Degradable polyurethane networks based on D,L-lacdde, glycohde, e-caprolactone, and trimethylene carbonate homopolyester and copolyester triols. Polymer, 1994, 35, 830-838. 

Figure 11 shows plots according to equation(lO) of stress-strain data for triol-based polyester networks formed from the same reactants at three initial dilutions (0% solvent(bulk), 30% solvent and 65% solvent). Only the network from the most dilute reactions system has a strictly Gaussian stress-strain plot (C2 = 0), and the deviations from Gaussian behaviour shown by the other networks are not of the Mooney-Rivlin type. As indicated previously, they are more sensibly interpreted in terms of departures of the distribution of end-to-end vectors from Gaussian form. 

Figure 11. Mooney-Rivlin plot of stress-strain data (32) for three triol-based polyester networks prepared from sebacoyl chloride and LHT240 at various initial dilutions in diglyme as solvent. Conditions P100 is 0% solvent P130 is 30% solvent PI 65 is 65% solvent.

Figure 3. Reaction coordinates for trans addition of BPDE l(+) to N2 on guanine to yield a triol adduct, BPT-N2(G). The torsional angles T], T2> T3,... define the pucker of the benzo ring. For binding to the other bases, N3(G) is replaced by Nl(A), Nl(G) and N3(C) for binding to N6(A), 06(G) and NU(c), respectively.

Synthetic transformations of the products of the intramolecular bis-silylation have been examined. The five-membered ring products derived from homopropargylic alcohols were hydrogenated in a stereoselective manner (Scheme ll).90 Oxidation of the products under the Tamao oxidation conditions (H202/F /base)96 leads to the stereoselective synthesis of 1,2,4-triols. This method can be complementary to the one involving intramolecular bis-silylation of homoallylic alcohols (vide infra). 

Phosphine complexes, osmium, 19 642 Phosphine coordination complexes, of uranium, 25 436 Phosphine derivatives, 19 28 Phosphine oxide(s), 11 495-496 19 66 predicted deviations from Raoult s law based on hydrogen-bonding interactions, 8 814t in salicylic acid manufacture, 22 8 Phosphine oxide diols/triols, 11 501 Phosphine selenides, 22 90 Phosphinic acid, 19 20, 54-55 Phosphinic anhydride, 11 499 Phosphinothricin acetyltransferase (PAT) proteins, 13 360 Phosphite esters, 19 20 Phosphites, in VDC polymer stabilization, 25 720... 

Triazole-based fungicides, 13 306, 595 Triazoles, 26 145, 9 288-289 Triazone, 2 640 s-Triazine-2,4,6-triol, S 200 Tribaloy T-800... 

In their pioneering work. Just and co-workers have described many interesting transformations of the Diels-Alder adducts of furan to methyl nitroacrylate (77 + 77 ) and to dimethyl acetylenedicarboxylate (53). The mixture of racemic adducts 77 + 77 was hydroxylated into the exo-cis-diols 125 + 125 , separable by crystallization. Treatment of the isopropylidene acetal obtained from 125 with diazabicyclo[5.4.0]undec-5-ene (DBU) gave a high yield of alkene 126. Ozonolysis followed by a reductive work-up with dimethylsulfide, then with NaBH4, gave a mixture of epimeric triols 127. Cleavage with sodium periodate afforded 2,5-anhydro-3,4-0-isopropylidene-DL-allose (128) in 15 % yield, based on methyl 2-nitroacrylate used. TTie same allose derivative was obtained from adduct 53. ... 

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