Free hydroxy group

Epoyy Resins. Titanates react with free hydroxy groups in epoxy resins or with the epoxy group itself ... 

Effective 1,7-asymmetric induction was observed in the analogous reactions between C-hydroxy-allylstannanes and aldehydes, although in this case the free hydroxy group was required126. 

Emulsion breakers are made from acrylic acid or methacrylic acid copolymerized with hydrophilic monomers [148]. The acid groups of acrylic acid and methacrylic acid are oxalkylated by a mixture of polyglycols and polyglycol ethers to provide free hydroxy groups on the molecule. The copolymers are made by a conventional method, for example, by free radical copolymerization in solution, emulsion, or suspension. The oxalkylation is performed in the presence of an acid catalyst, the acid being neutralized by an amine when the reaction is complete. 

It is known that ammonium polyphosphate tends to dissociate liberating ammonia above 300 C and the resulting free hydroxy groups condense giving crosslinked structures (ultraphosphate) with elimination of water (28.29) ... 

High chemoselectivity is observed in this ruthenium-catalyzed isomerization of allylic alcohols. Simple primary and secondary alcohols and isolated double bonds are not affected by these catalysts. Furthermore, free hydroxy group is essential for this catalysis. The reaction of l-acetoxycyclododec-2-ene-4-ol furnished 4-acetoxycyclododecanone in high yield (Scheme 14).37... 

The neomycin molecule contains both free amino and free hydroxy groups. Many workers have exploited the possibility of chemical de-rivatisation at these positions in attempts to reduce the toxicity of the parent antibiotic. Substitution of methane sulphonate groups at the amino nitrogen has been reported by Umezawa et al83,84 and by Boissier et al . Both groups of workers described the derivative to be less toxic... 

Norrild and coworkersd showed that this structure is only valid as an initial complex formed under completely non-aqueous conditions. In the presence of water, a rapid rearrangement from the a-D-glucopyranose form to the a-D-glucofuranose occurs. In the latter form, all five free hydroxy groups of glucose are covalently bound to the sensor molecule (Figure B.10.4.2). 

As depicted in Fig. 6, syntheses of enantiomerically pure 116 and 117 have been carried out [236]. Lipase AK-catalysed asymmetric acetylation of meso-2,4-dimethyl-1,5-pentanediol A yielded (2R,4S)-5-acetoxy-2,4-dimethylpen-tanol B. Protection of the free hydroxy group as the terf-butyldimethylsilyl (TBS) ether, saponification of the acetate, and oxidation furnished the aldehyde C. Reaction of C with ethylmagnesium bromide gave a diastereomeric mixture of the corresponding secondary alcohols which could be resolved by asym-... 

It has been demonstrated by Pancrazi, Ardisson and coworkers that an efficient kinetic resolution takes place when an excess (2 equivalents) of the racemic titanated alkenyl carbamate rac-334a (R = Me) is allowed to react with the enantiopure )-hydroxyaldehyde 341 or alternatively the corresponding y-lactol 340, since the mismatched pair contributes to a lower extent to the product ratio (equation 91) . Under best conditions, the ratio of the enantiomerically pure diastereomers 3,4-anti-4,5-syn (342) and 3,4-anti-4,5-anti (343) is close to 14 1. Surprisingly, approximately 9% of the iyw,iyw-diastereomer 344 resulted when the starting (ii)-crotyl carbamate was contaminated by the (Z)-isomer. The reasons which apply here are unknown. Extra base has to be used in order to neutrafize the free hydroxy group. The pure awft, awfi-product 345 was obtained with 85% yield from the reaction of the (W-oxy-substituted titanate rac-334b and lactol 340. 345 is an intermediate in the asymmetric synthesis of tylosine . ... 

Dyeable (free hydroxy groups), hydrophilic (comfortable), stable, low price, poor wash and wear characteristics... 

To acetylate the free hydroxy groups of a polyester,a solution of 15 g of freshly distilled acetic anhydride (bp 140 °C) in 35 g of freshly distilled dry pyridine is prepared.The solution, which turns slightly yellow with time, is stored in a dark bottle. 

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