Styrene oxide hydration

P. M. Dansette, V. B. Makedonska, D. M. Jerina, Mechanism of Catalysis for the Hydration of Substituted Styrene Oxides by Hepatic Epoxide Hydrase , Arch. Biochem. Biophys. 1978, 187, 290 - 298. 

A drum of styrene oxide was punctured and the spillage absorbed into an hydrated silate absorbent, the combination swept up and drummed up for disposal. The drum became hot and started emitting copious white fumes. It was not possible to duplicate this behaviour in the laboratory unless acid or base catalyst was also present [1], Absorbents may be inert, epoxides are not but contain considerable strain energy which will be liberated by autoreaction or nucleophilic substitution by, e.g. water. Only a catalyst is needed neither silicates nor floor-sweepings can be guaranteed free of these [2]. 

Hydration of epoxides catalyzed by epoxide hydrolase is involved in both detoxication and intoxication reactions. With high concentrations of styrene oxide as a substrate, the relative activity of hepatic microsomal epoxide hydrolase in several animal species is rhesus monkey > human = guinea pig > rabbit > rat > mouse. With some substrates, such as epoxidized lipids, the cytosolic hydrolase may be much more important than the microsomal enzyme. 

As demonstrated below, a Lewis acid-mediated reaction was utilized in the synthesis of dihydro[b furan-based chromen-2-one derivatives from l-cyclopropyl-2-arylethanones and allenic esters <070L4017>. The TiCh-catalyzed anti-Markovnikov hydration of alkynes, followed by a copper-catalyzed O-arylation was applied to the synthesis of 2-substituted benzo[6]furan <07JOC6149>. In addition, benzo[6]furan-based heterocycles could be made from chloromethylcoumarins <07SL1951>, substituted cyclopropanes <07AGE1726>, as well as benzyne and styrene oxide <07SL1308>. On the other hand, DBU-mediated dehydroiodination of 2-iodomethyl-2,3-dihydrobenzo[6]furans was also useful in the synthesis of 2-methylbenzo[Z>]furans <07TL6628>. 

Hydration Flounder, Sheepshead Styrene oxide, Benzo la] pyrene 4,5-oxide,... 

Nucleophilic. In view of the ability of epoxides to become hydrated to the diol under aqueous alkaline conditions, the analogous addition of water to epoxides by enzymes will be considered in this section. The en mes responsible for epoxide hydration (epoxide hydrases) in animal liver systems have been purified, assayed using [7- H]styrene oxide,and tested for substrate and inhibitor -ass specificity. The current interest in these epoxide hydrases is mainly due to their close association with aryl monooxygenase enzymes and thus the total metabolism of olefinic and arene substrates via epoxides) in animals. The isolation of the antibacterial compounds aeroplysinin-1 (358) and aeroplysinin-2 (359) from the sponge Verongia aerophoba might be explained by the initial enzymatic formation of the unstable arene oxide (357), which can subsequently be hydrated by an epoxide hydrase enzyme, to form what the authors consider... 

A lead(ii) coordination polymer 4, prepared from disodium 1,5-naphtha-lenedisulfonate and 1,10-phenanthroline with lead acetate hydrate (Figure 22.2) has been reported to catalyse the ring opening of epoxides (styrene oxide, cyclohexene oxide, cyclopentene oxide with anilines) with very high yield. ... 

Sulfonated poly(arylene ether)s have shown promise for durability in fuel cell systems, while poly-(styrene)- and poly(imide)-based systems serve as model systems for studying structure-relationship properties in PEMs because their questionable oxidative or hydrolytic stability limits their potential application in real fuel cell systems. Sulfonated high performance polymer backbones, such as poly(phe-nylquinoxaline), poly(phthalazinone ether ketone)s, polybenzimidazole, and other aromatic or heteroaromatic systems, have many of the advantages of poly-(imides) and poly(arylene ether sulfone)s and may offer another route to advanced PEMs. These high performance backbones would increase the hydrated Tg of PEMs while not being as hydrolytically sensitive as poly(imides). The synthetic schemes for these more exotic macromolecules are not as well-known, but the interest in novel PEMs will surely spur developments in this area. 

Methanol Formaldehyde Ethylene Propylene oxide Phenol 1,4-Butanediol Tetrahydrofuran Ethylene glycol Adipic acid Isocyanates Styrene Methyl methacrylate Methyl formate Two-step, via CH4 steam reforming Three-step, via methanol Cracking of naphtha Co-product with t-butyl alcohol or styrene Co-product with acetone Reppe acetylene chemistry Multi-step Hydration of ethylene oxide Multi-step Phosgene chemistry Co-product with propylene oxide Two-step, via methacrolein Three-step, via methanol... 

Another example is Dias Analytics styrenic membrane based on the well-known block copolymer styrene-ethylene/butylene-styrene family.This membrane has good conductivity 0.07 to 1.0 S/cm when fully hydrated. It showed reasonable performance but had poor oxidative stability due to the susceptibility of its aliphatic backbone to peroxide attack. 

R,8R)-dihydrodiol from the (+)-(7R,8S)-oxide at low conversion. A similar situation has been proposed to explain the kinetics of hydration of the enantiomers of styrene 7,8-oxide. 

Addition Reactions - An examination of the photochemical behaviour of styrenes encapsulated in zeolites has shown that both oxidation and hydration take place and one of the major reactions encountered is the formation of 2-phenylethanol. Irradiation (X,>300 nm) of the allenes (43) and (44) in deuteriochloroform solution in the presence of a 1 1 molar ratio of (PhS)2 and (PhSe)2 provides a convenient method for thioselenation and affords good yields of adducts such as (45, 99%, 22 78 E Z ratio) and (46, 75%, 40 60 E Z ratio), respectively. ... 

A series of well-defined A-B block copolymers of polystyrene-block-polyethylene oxide (PS-PEO) were synthesised [6] and used for the emulsion polymerisation of styrene. These molecules are ideal as the polystyrene (PS) block is compatible with the PS formed, and thus it forms the best anchor chain. The PEO chain (the stabilising chain) is strongly hydrated with water molecules and extends into the aqueous phase where it forms the steric layer necessary for stabilisation. 

Polystyrene-supported iodosylbenzene (22) (loading of -lO groups up to 1.50 mmol g" ) has been prepared by a solvent-free reaction of poly[(diacetoxyiodo)styrene] (4) with sodium hydroxide (Scheme 5.11) [22]. Elemental analysis of polymer 22 indicates that the -lO groups are partially hydrated as shown in structure 23. This resin has been successfully used for efficient oxidation of a diverse collection of alcohols to aldehydes and ketones in the presence of BF3-Et20. Reagent 22 can also be employed as efficient co-catalyst in combination with RuCls in the catalytic oxidation of alcohols and aromatic hydrocarbons, respectively, to the corresponding carboxylic acids and ketones using Oxone as the stoichiometric oxidant [22]. 

PEG-75 distearate PEG-2 laurate SE PEG-20 laurate PEG-32 laurate PEG-75 laurate PEG-20 oleate PEG-32 oleate PEG-75 oleate PEG-300 oleate PEG-2 stearate PEG-20 stearate PEG-32 stearate PEG-75 stearate PEG-300 stearate PEG-1500 stearate Polyglyceryl-10 decastearate Propylene glycol hydroxystearate Propylene glycol myristate Pyrophyllite Silica, amorphous hydrated Silica, hydrated Sodium styrene/acrylates/divinylbenzene copolymer Stannic oxide Stearamide Stearamide DEA-distearate... 

Styrene and other phenyl-substituted olefins exhibit a similar behavior. This novel type of reaction has been termed "oxidation-reduction hydration". 

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