Phenyl- propene oxide

In a subsequent paper, the authors developed another type of silica-supported dendritic chiral catalyst that was anticipated to suppress the background racemic reaction caused by the surface silanol groups, and to diminish the multiple interactions between chiral groups at the periphery of the dendrimer 91). The silica-supported chiral dendrimers were synthesized in four steps (1) grafting of an epoxide linker on a silica support, (2) immobilization of the nth generation PAMAM dendrimer, (3) introduction of a long alkyl spacer, and (4) introduction of chiral auxiliaries at the periphery of the dendrimer with (IR, 2R)-( + )-l-phenyl-propene oxide. Two families of dendritic chiral catalysts with different spacer lengths were prepared (nG-104 and nG-105). 

Benzenetellurinyl trifluoroacetate and 1-trimethylsily 1-2-propenes reacted at 20° in 1,2-dichloroethane in the presence of boron trifluoride etherate to give allyl phenyl tellurium oxides in almost quantiative yields. These compounds were not isolated but reduced to allyl phenyl telluriums with hydrazine hydrate or converted to allylamines2. 

Its pentadeuterated derivative, phenyl-(D5)propene oxide, under the same conditions, leads to the elimination of one molecule of deuterated (or not) water. The unambiguous attribution of the signal obtained requires precise measurements of centroids for these cluster peaks. 

CAS 122-60-1 EINECS/ELINCS 204-557-2 Synonyms 1,2-Epoxy-3-phenoxypropane 2,3-Epoxypropyl phenyl ether Glicidyl phenyl ether Glycidyl phenyl ether Oxirane, (phenoxymethyl)- PGE Phenol glycidyl ether 3-Phenoxy-1,2-epoxypropane Phenoxy-propene oxide Phenoxypropylene oxide Phenyl-2,3-epoxypropyl ether Classification Aromatic epoxy ether Empirical C5FI10O2... 

A study of the regioselectivity of the 1,3-dipolar cycloaddition of aliphatic nitrile oxides with cinnamic acid esters has been published. AMI MO studies on the gas-phase 1,3-dipolar cycloaddition of 1,2,4-triazepine and formonitrile oxide show that the mechanism leading to the most stable adduct is concerted. An ab initio study of the regiochemistry of 1,3-dipolar cycloadditions of diazomethane and formonitrile oxide with ethene, propene, and methyl vinyl ether has been presented. The 1,3-dipolar cycloaddition of mesitonitrile oxide with 4,7-phenanthroline yields both mono-and bis-adducts. Alkynyl(phenyl)iodonium triflates undergo 2 - - 3-cycloaddition with ethyl diazoacetate, Ai-f-butyl-a-phenyl nitrone and f-butyl nitrile oxide to produce substituted pyrroles, dihydroisoxazoles, and isoxazoles respectively." 2/3-Vinyl-franwoctahydro-l,3-benzoxazine (43) undergoes 1,3-dipolar cycloaddition with nitrile oxides with high diastereoselectivity (90% de) (Scheme IS)." " ... 

The degradation products of GOS were 1,3-dimethyl pyrogallol (HI), 2-(2 ,6 dimethoxy phenoxy)-2-propenal (Vni), 2-(2, 6 -dimethoxy phenoxy)-3-hydroxypropanal (XII), and GOS-Dimer. These products show that the reaction includes oxidative polymerization and the cleavage of -0-4 ether linkage following the alkyl-phenyl cleavage. This depolymerization pathway of GOS is also similar to that of SOS (Table I). 

The first variant works with isobutane as the hydroperoxide precursor, which is oxidized to TBHP by molecular oxygen. During the epoxidation of propene, TBHP is transformed to ferf-butanol, which is converted to methyl ferf-butyl ether. The second procedure employs ethylbenzene, which is oxidized by molecular oxygen to phenyl ethyl hydroperoxide, which transfers an oxygen to propene and so is reduced to phenylethanol. This by-product of the process is converted to styrene, a versatile bulk chemical. 

Another cycloaddition to an a,(3-unsaturated compound involves the reaction of nitrile oxides with 3-methoxy- or 3-methylthio-1 -phenyl-2-propene-1 -one (Scheme 6.18) (133,134). The isoxazoles that are isolated are considered to arise from the respective intermediate isoxazolines by subsequent elimination of methanol or methanethiol. The regioselectivity observed was attributed to the presence of substituents with strong electron-donating ability, and this was accommodated in terms of the FMO theory (133,134). 

The asymmetric oxidation of sulphides to chiral sulphoxides with t-butyl hydroperoxide is catalysed very effectively by a titanium complex, produced in situ from a titanium alkoxide and a chiral binaphthol, with enantioselectivities up to 96%342. The Sharpless oxidation of aryl cinnamyl selenides 217 gave a chiral 1-phenyl-2-propen-l-ol (218) via an asymmetric [2,3] sigmatropic shift (Scheme 4)343. For other titanium-catalysed epoxidations, see Section V.D.l on vanadium catalysis. 

The presence of a 3-methyl group in 53 changes the reaction course. When the oxidant Se02 is used in more than twofold excess relative to 3-methyl-2//-tellurachromene, bis[2-(3 -propene-2 -methyl-1 -al)phenyl]-ditelluride 56a is formed in 60% yield. When a smaller relative amount of Se02 is used in this reaction, aldehyde 56a is formed along with the product of selenium insertion into the Te—Te bond, 58 (in 15% yield [83JOM(258)163]. 

More than 300 compounds had been identified in cocoa volatiles, 10% of which were carbonyl compounds (59,60). Acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, phenylacetaldhyde and propanal were products of Strecker degradation of alanine, valine, leucine, isoleucine, phenyl-acetaldehyde, and a-aminobutyric acid, respectively. Eckey (61) reported that raw cocoa beans contain about 50-55% fats, which consisted of palmitic (26.2%), stearic (34.4%), oleic (37.3%), and linoleic (2.1%) acids. During roasting cocoa beans these acids were oxidized and the following carbonyl compounds might be produced - oleic 2-propenal, butanal, valeraldehyde, hexanal, heptanal, octanal, nonanal, decanal, and 2-alkenals of Cg to C-q. Linoleic ethanal, propanal, pentanal, hexanal, 2-alkenals of to C q, 2,4-alkadienals of Cg to C-q, methyl ethyl ketone and hexen-1,6-dial. Carbonyl compounds play a major role in the formation of cocoa flavor components. 

Using ammonium cerium(IV) nitrate (CAN) as the oxidant for the azide anion, the azido radicals are trapped by alkenes, to form, ultimately, /i-azido nitrates84 cerium azide species may be considered as intermediates. Alkenes conjugated with carbonyl groups are recovered intact. The stereochemistry of the adducts from acenaphthylene and indene was trans, as shown by H-NMR studies (/AX < 2 Hz for the acenaphthylene adduct), but with (-Eyi-phenyl-l-propene both syn and anti additions were formed. 

The oxidation of glycols occurred preferentially at the secondary alcohol group. Thus, propene glycol and 2-phenyl-l,2-ethanediol afforded hydroxyacetone and P-hydroxyacetophenone, respectively, as the major product [115]. Ethene glycol... 

The asymmetric [2,3]sigmatropic rearrangement of several other allyl aryl selenides has been reported, but only moderate selectivities are observed [27] (Scheme 18). The oxidation of cinnamyl and geranyl selenides derived from L-prolinol with MCPBA at -90°C afforded the chiral l-phenyl-2-propen-l-ol and linalool with moderate enantiomeric excess, respectively. 

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