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Esters, glycidic

The glycidic esters are of interest primarily because upon hydrolysis aud decarboxylation they aflFord aldehydes (if ClCHjCOOEt is used) or ketones (if substituted chloroacetic esters- ClCHRCOOEt are employed) having a higher carbon content than the original aldehyde or ketone. Thus (I) gives o-phenyl-propionaldehyde or hydratropaldehyde (II) ... [Pg.906]

The decomposition of a glycidic ester to an aldehyde and carbon dioxide may involve the formation of a quasi six-membered ring, followed by the shift of three electron pairs ... [Pg.906]

Benzilic acid rearrangement Benzoin reaction (condensation) Blanc chloromethylation reaction Bouveault-Blanc reduction Bucherer hydantoin synthesis Bucherer reaction Cannizzaro reaction Claisen aldoi condensation Claisen condensation Claisen-Schmidt reaction. Clemmensen reduction Darzens glycidic ester condensation Diazoamino-aminoazo rearrangement Dieckmann reaction Diels-Alder reaction Doebner reaction Erlenmeyer azlactone synthesis Fischer indole synthesis Fischer-Speior esterification Friedel-Crafts reaction... [Pg.1210]

A variation of this idea utilizes the glycidic ester (175). This underwent condensation with thioureas and phenyl dithiocarbamate to give (176 R =NR2, SPh, respectively) (71BSF4021). [Pg.130]

Synthesis of glycidic esters (amides) from an aldehyde or ketone and an a-haloester (amide). [Pg.88]

Other methods for the preparation of cyclohexanecarboxaldehyde include the catalytic hydrogenation of 3-cyclohexene-1-carboxaldehyde, available from the Diels-Alder reaction of butadiene and acrolein, the reduction of cyclohexanecarbonyl chloride by lithium tri-tcrt-butoxy-aluminum hydride,the reduction of iV,A -dimethylcyclohexane-carboxamide with lithium diethoxyaluminum hydride, and the oxidation of the methane-sulfonate of cyclohexylmethanol with dimethyl sulfoxide. The hydrolysis, with simultaneous decarboxylation and rearrangement, of glycidic esters derived from cyclohexanone gives cyclohexanecarboxaldehyde. [Pg.15]

Table 1. Cleavage of Glycidic Esters, Glycidic Amides, and Glycidic Nitriles by Hydrogen Fluoride-Pyridine Complex 110,11]... Table 1. Cleavage of Glycidic Esters, Glycidic Amides, and Glycidic Nitriles by Hydrogen Fluoride-Pyridine Complex 110,11]...
Darzens glycidic ester condensation generally involves the condensation of an aldehyde or ketone 2 with the enolate of an a-halo ester 1 which leads to an a,P-epoxy ester (a glycidic ester) (3). Thus the reaction adds two carbons to the electrophile however, the reaction has been primarily developed as a one-carbon homologation method. That is, subsequent to the condensation, the ester is saponified and decarboxylation ensues to give the corresponding aldehyde or ketone 5.2... [Pg.15]

In recent years, several modifications of the Darzens condensation have been reported. Similar to the aldol reaction, the majority of the work reported has been directed toward diastereo- and enantioselective processes. In fact, when the aldol reaction is highly stereoselective, or when the aldol product can be isolated, useful quantities of the required glycidic ester can be obtained. Recent reports have demonstrated that diastereomeric enolate components can provide stereoselectivity in the reaction examples include the camphor-derived substrate 26, in situ generated a-bromo-A -... [Pg.17]

Recendy, Darzens reaction was investigated for its synthetic applicability to the condensation of substituted cyclohexanes and optically active a-chloroesters (derived from (-)-phenylmenthol). In this report, it was found that reaction between chloroester 44 and cyclohexanone 43 provided an 84% yield with 78 22 selectivity for the axial glycidic ester 45 over equatorial glycidic ester 46 both having the R configuration at the epoxide stereocenter. [Pg.19]

Of interest is a recent report of a rapid synthesis of efaroxin (51), a potent, selective O2 adrenoceptor antagonist, using Darzens Reaction. Accordingly, a-bromoester 48 was condensed with aldehyde 47. The glycidic ester (49) was then hydrogenated to reduce the more labile epoxide bond to give alcohol 50. Subsequent standard transformations subsequently lead to a completed 4-step synthesis of efaroxin. o... [Pg.20]

A number of 5-hydroxy-2-oxotetrahydro-l,3-oxazine derivatives can also be formed from glycide esters of carbamic acid ... [Pg.320]

An a ,/3-epoxycarboxylic ester (also called glycidic ester) 3 is formed upon reaction of a a-halo ester 2 with an aldehyde or ketone 1 in the presence of a base such as sodium ethoxide or sodium amide. Mechanistically it is a Knoevenagel-type reaction of the aldehyde or ketone 1 with the deprotonated a-halo ester to the a-halo alkoxide 4, followed by an intramolecular nucleophilic substitution reaction to give the epoxide 3 ... [Pg.81]

Aldehydes and ketones condense with a-halo esters in the presence of bases to give ot,p-epoxy esters, called glycidic esters. This is called the Darzens condensation. The reaction consists of an initial Knoevenagel-type reaction (16-41), followed by an internal Sn2 reaction (10-13) ° ... [Pg.1230]


See other pages where Esters, glycidic is mentioned: [Pg.906]    [Pg.907]    [Pg.95]    [Pg.94]    [Pg.99]    [Pg.115]    [Pg.202]    [Pg.1]    [Pg.15]    [Pg.15]    [Pg.21]    [Pg.81]    [Pg.82]    [Pg.4]    [Pg.35]    [Pg.1052]    [Pg.1230]    [Pg.1230]    [Pg.1670]   
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2.7- Dioxabicyclo[4.1 .OJheptanes Darzens glycidic ester condensation

Acrylonitrile, a-acetoxypreparation Darzens glycidic ester condensation

Aldehydes from glycide esters

Bovine serum albumin Darzens glycidic ester condensation

Carboxylation Darzens glycidic ester condensation

Carboxylic acids, a-halodianions Darzens glycidic ester condensation

Carboxylic acids, a-ketopreparation Darzens glycidic ester condensation

Carboxylic esters, glycidic, from

Cyclohexanones Darzens glycidic ester condensation

Cyclopropanes Darzens glycidic ester condensation

Darzens glycidic ester condensation

Darzens glycidic ester condensation asymmetric

Darzens glycidic ester condensation intramolecular

Darzens glycidic ester condensation mechanism

Darzens glycidic ester condensation modifications

Darzens glycidic ester condensation phase-transfer catalysis

Darzens, glycidic ester

Darzens, glycidic ester synthesis

Darzen’s glycidic ester synthesis

Epoxides Darzens glycidic ester condensation

Esters Darzens glycidic ester condensation

Esters glycidic ester condensation

Esters glycidic, synthesis

Esters, a-halo Darzens glycidic ester condensation

Esters, vinylogous Darzens glycidic ester condensation

Ethyl chloroacetate, glycidic esters from

Glycid

Glycid ester condensations

Glycidates

Glycide

Glycidic

Glycidic acid ester

Glycidic acid esters aldehydes

Glycidic acid esters chiral, synthesis

Glycidic acid esters ketones

Glycidic acid methyl ester

Glycidic acid, /3-methyl- -phenyl ETHYL ESTER

Glycidic ester condensation

Glycidic ester formation

Glycidic ester, condensation synthesis

Glycidic esters cleavage

Glycidic esters from aldehydes

Glycidic esters from amides

Glycidic esters from ketones

Glycidic esters preparation

Glycidic esters, 3-substituted

Glycidic esters, acids, nitriles

Glycidic esters, also

Glycidic esters, ring opening

Glycidic thiol esters

Glycidic thiol esters preparation

Ketones Darzens glycidic ester condensation

Lithium bis amide Darzens glycidic ester condensation

Nitriles Darzens glycidic ester condensation

Overlap control Darzens glycidic ester condensation

Pfizer Central Research, Groton, CT, USA 13 Darzens Glycidic Ester Condensation

Rearrangement glycidic ester

Rearrangement of Glycidic Acid Ester

Silane, trimethylDarzens glycidic ester condensation

Silicon compounds Darzens glycidic ester condensation

Sulfones Darzens glycidic ester condensation

The Darzene glycidic ester condensation

The Darzens glycidic ester condensation

Thiol esters Darzens glycidic ester condensation

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