Reaction with propylene oxide

Carboxvalkvlation of Propylene Oxide. These reagents were also used in a similar carboxyalkylation scheme to prepare methyl 3-hydroxybutyrate by reaction with propylene oxide (Equation 3). This might represent a way to prepare substitute 1,3 diols(48) following reduction of the ester or reactive monomers by pyrolys is/dehydration. 

Materials. Hydroxypropyl lignin (HPL) Organosolv (aqueous ethanol) lignin from aspen, supplied by Repap Technologies Inc. (formerly the Biological Energy Corporation) of Valley Forge, PA, was hydroxypropylated by reaction with propylene oxide in the usual manner (9). This derivative was isolated and purified as described previously (9). 

These results encouraged us to further functionalized the remaining secondary amine groups of the anchored 1 through reaction with propylene oxide. 

Rhodium and ruthenium complexes of CHIRAPHOS are also useful for the asymmetric hydrogenation of p-keto esters. Dynamic kinetic resolution of racemic 2-acylamino-3-oxobutyrates was performed by hydrogenation using ((5,5)-CHIRAPHOS)RuBr2 (eq 3). The product yields and enantiomeric excesses were dependent upon solvent, ligand, and the ratio of substrate to catalyst. Under optimum conditions a 97 3 mixture of syn and anti p-hydroxy esters was formed, which was converted to o-threonine (85% ee) and D-allothreonine (99% ee) by hydrolysis and reaction with propylene oxide. 

Starches have been chemically modified to improve their solution and gelling characteristics for food applications. Common modifications involve the cross linking of the starch chains, formation of esters and ethers, and partial depolymerization. Chemical modifications that have been approved in the United States for food use, involve esterification with acetic anhydride, succinic anhydride, mixed acid anhydrides of acetic and adipic acids, and 1-octenylsuccinic anhydride to give low degrees of substitution (d.s.), such as 0.09 [31]. Phosphate starch esters have been prepared by reaction with phosphorus oxychloride, sodium trimetaphosphate, and sodium tripolyphosphate the maximum phosphate d.s. permitted in the US is 0.002. Starch ethers, approved for food use, have been prepared by reaction with propylene oxide to give hydroxypropyl derivatives [31]. 

Polyurethane chemolysis by reaction with ammonia or various amines has been described in the literature. Sheratte92 has proposed a process based on polyurethane decomposition by various agents. Several examples were provided for polyurethane degradation with ethanolamine (120 °C), ammonia and ammonium hydroxide (180 °C), diethylene triamine (200 °C) and other basic reagents. In all cases the process involves, simultaneously or subsequently, reaction with propylene oxide, which allows the different amines obtained to be quantitatively converted into polyols according to the reaction shown in Scheme 2.6. The polyols derived from this process were used in the reformulation of new polyurethanes by polymerization with the corresponding isocyanate, and were suitable for application in rigid foams. 

Scheme 2.6 Conversion ofprimary amines into polyols by reaction with propylene oxide.92...

Reactions of substituted prop-2-ynyl lithium compounds can similarly give acetylenic and allenic products. Huynh and Linstrumelle prepared the lithium acetylide 11 and confirmed its structure by NMR spectroscopy. Reaction with propylene oxide then gave a mixture of 12 (45%) and 13 (55%), showing that both organo-lithium species can react to give either allenic or acetylenic products. 

J. -A. Han and J. N. BeMiller, Influence of reaction conditions on MS values and physical properties of waxy maize starch derivatized by reaction with propylene oxide, Carbohydr. Polym., 64 (2006) 158—162. 

A reaction with propylene oxide produces the nontoxic propylene glycol alginate, which, unlike the alkali alginates, does not gel at high concentrations. Typical uses are as stabilizers for puddings, ice cream, orange juice, beer foam (in the United States), inks, cosmetics, etc. 

It should be noted ethylene oxide is explosive and its rate of reaction with alkali cellulose is very rapid so runaway polymerizations may occur. Reactions with propylene oxide are more easily controlled and runaway polymerizations do not occur. 

Stepanov EG, Podgomova VA, Ustavshchikov BF (1976) Effect of the structure of the carboxylic acid on the reactivity in the reaction with propylene oxide. Osnovn Organ Sintez i Neftekhimiya 6 29-31... 

The chloral/melamine reaction product of Preparation 3-6 has also been shown to be capable of reaction with propylene oxide in the presence of BF3 etherate to give a compound useful for flame retarding polyurethane foam [73]. It is suggested that the structure of this compound is ... 

Having established that the polymerization of propylene oxide by the zinc hexacyanocobaltate complex catalyst proceeds in the absence of a chain termination reaction, it was of interest to study separately the chain propagation reaction. A non-termi-nated polymer "seed" was prepared and its rate of reaction with propylene oxide was studied. The results of a series of these seeded polymerizations carried out at 30°, 40° and 50° are given in Figvire 6, where log [M]o/[M]t is plotted against time. 

Last isochormanic system drawn, l,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclo-penta-( )-2-benzopyran, which was developed in the middle 1960 (3) by Beets and Heer-inga from IFF is know also commercially as, e.g., Galaxolide, Abbalide. This molecule is S5mthesized as follows there is a condensation-cyclization stage of tert-smy alcohol and a-methyl styrene in acidic conditions to obtain the indane system, followed by a Friedel-Crafts reaction with propylene oxide to get the side chain. The side chain is finally closed to the isochromanic system using formaldehyde ... 

The most important epoxide resins are oligomers produced from the reaction of bisphenol A and epichlorhydrin. Bisphenol A is prepared from phenol and acetone, and need not be pure. Epichlorhydrin is made from propylene via the hydrochlorination reaction with propylene oxide. Diglycidyl ether is produced in the reaction of bisphenol A with excess epichlorhydrin (2-3 times stoichiometry), in an alkaline solution to prevent higher homo-logues being formed (n = 1. in Reaction 12). 

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