Glycidic esters preparation

B. Methyl 3-methyl-2-furoate. The crude glycidic ester prepared as described above is placed in a 300-ml. flask which is attached to a 12-cm. column filled with %6-inch glass helices (or a 50-cm. simple Vigreux column) and heated in a liquid bath. When the pot temperature reaches about 160°, or before, methanol begins to distil. Heating is continued until the distillation of methanol essentially ceases and about the theoretical amount (64 g.) has been collected. After the heating bath has been allowed to cool, the product is distilled at reduced pressure b.p. 72-78°/8 mm., yield 91-98 g. (65-70%) (Note 7). The ester solidifies in the receiver as an essentially pure compound, m.p. 34.5-36.5° (Note 8). 

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. 

Geranyl chloride can be prepared from geraniol by the careful use of triphenylphosphine in carbon tetrachloride. Tris(dimethylamino)phosphine reacts with carbon tetrachloride to form the complex (42) which can be used to form the enol esters (43) from acid anhydrides. Similarly, aldehydes form the alkenes (44), and esters or amides of trichloroacetic acid are converted to glycidic esters. ... 

Apart from the reaction of cyclohexanecarboxylic acid with methyllithium, cyclohexyl methyl ketone has been prepared by the reaction of cyclohexylmagnesium halides with acetyl chloride or acetic anhydride and by the reaction of methylmagnesium iodide with cyclohexanecarboxylic acid chloride. Other preparative methods include the aluminum chloride-catalyzed acetylation of cyclohexene in the presence of cyclohexane, the oxidation of cyclohexylmethylcarbinol, " the decarboxylation and rearrangement of the glycidic ester derived from cyclohexanone and M)utyl a-chloroj)ropionate, and the catalytic hydrogenation of 1-acetylcycIohexene. "... 

A benzoazathiazepine provides the nucleus for a stmcturally unusual calcium channel blocker. This was, incidentally, one of the first of the growing class of dmgs provided as the pure biologically active enantiomer. The key, and very carefully studied, reaction to the preparation of this compound consists of the opening of the racemic glycidic ester (27-2) with nitrothiophenol (27-1). The reaction proceeds to... 

Other preparations of 2-iminothiazolidin-4-ones which are discussed in the review by Brown139 utilize the reactions of thiourea with a-hydroxy acids,146 ethyl diazoacetate,73 glycidic esters,74,147 cinnamic acid,148 unsaturated diacids (fumaric, maleic, and citraconic) or their esters or imides,149-152 and propiolic esters.153,154 There has been considerable controversy in the literature surrounding the propiolic ester synthesis since many workers have proposed that the products are 1,3-thiazines (see Section IV, B, 1). The pertinent papers in this controversy have been summarized by Cain and Warrener.155 Nagase158 has recently settled the argument in favor of the 2-iminothiazolidin-4-... 

The methoxy derivatives may be treated directly o-methoxyphenyl-acetone, heated with hydrobroniic acid in acetic acid, gives 2-methyl-benzofuran.326 o-Methoxylated phenylacetones are readily prepared by glycidic synthesis from o-methoxylated aromatic aldehydes the intermediate glycidic ester (127) can be directly converted by pyridine hydrochloride into a 2-alkylbenzofuran in 40-80% yield.105... 

The present procedure is that described by the submitter.3 It is an improved modification of that described by Hoover and Hass4 for the corresponding para isomer. o-Methoxyphenyl-acetone has also been prepared from the glycidic ester.5... 

Glycidic esters are prepared by the reaction of an aldehyde or ketone with an a-haloester in the presence of base (sodium ethoxide, sodamide, finely divided sodium or potassium t-butoxide) (the Darzens glycidic ester condensation). 

Toda, F., Takumi, H., and Tanaka, K. (1995) A Simple Preparative Method for Optically Active Glycidic Esters, Tetrahedron Asymm., 6, 1059-1062. 

This nitrate ester of glycide is prepared from dinitroglycerine by splitting off one HN03 molecule with concentrated alkali. It is the anhydride of glyceriN mononitrate. 

Burness24, 79 prepared 3-methyl-2-carbomethoxyfuran in 55% yield from jS-ketobutyracetal, with rearrangement of the intermediate glycidic ester ... 

Aromatic and aliphatic aldehydes have been prepared in good yields by the decarboxylation and isomerization of the corresponding glycidic acids. Esters of the latter are obtained by treating a ketone with ethyl chloro-acetate in the presence of sodium amide (method 127). The glycidic esters are first converted to the sodium salts with sodium ethoxide and then treated with aqueous hydrochloric acid under gentle reflux. By this procedure, a-phenylpropionaldehyde has been prepared from acetophenone in an over-all yield of 38%. Other details have been discussed. ... 

Examples are presented below to illustrate the varied possibilities of utilizing the method. Glycidic esters can be prepared from the a-bromo esters with LiN(SiMe3)2 mainly (72-86%) the trans isomer is formed (Eq. 75). ... 

Darzens, G. New Method of Preparing Glycidic Esters. Compt. rend. 1911, 151, 883-884. 

Preparation. Useful in glycidic ester condensation because of avoidance of self-condensation. ... 

---