Acetic acid, Acetoxy-, ethyl ester

Ethoxyacetamide (Athoxyacetamid or Athyl-atherglykolsaureamid, in Ger), C2H5O.CH.2CONH2 mw 103.12, N 13-58% plates (from benz) mp 82.5°(sublimes), bp 225° at 75mm Hg easily sol in w, ale, eth, benz and CS2. It can be prepd by action of aqueous ammonia on ethyl ester of ethoxy-acetic acid or by action of ammonia on acetoxy-acetyl chloride in ether... 

In a third microreactor, the anion of 4-ferf-butyl l-ethyl-2-(diethox-yphosphoryl)succinate was prepared in situ using sodium ethoxide 237 (in EtOH) and the Wittig-Horner olefination with benzaldehyde 116 performed using a residence time of 47 min to afford (E)-ferf-butyl-l-ethyl-2-benzylidenesuccinate 238 in excellent selectivity (89% yield). In a fourth reactor, the acid-catalyzed (TFA 239) ferf-butyl ester deprotection was achieved using a residence time of 5 min at 34 °C and employing DCM as the reaction solvent to afford (E)-3-(ethoxycarbonyl)-4-phenylbut-3-enoic acid 246 in 82% yield. The deprotection was subsequently followed by a Friedel-Crafts acylation, using triethylamine 14 and acetic anhydride 37, to afford 4-acetoxy-naphthalene-2-carboxylic acid ethyl ester 241 in quantitative yield when conducted at 130 °C (residence time = 47 min). 

Enol esters are much more labile to hydrogenolysis than enol ethers. Thus, 1-acetoxy-cyclohexene and ethyl 3-acetoxycrotonate are almost quantitatively hydrogenolyzed over Adams platinum in ethanol or acetic acid (eqs. 13.46 and 13.47).91 92... 

The products obtained by the action of peracids upon 3-alkoxy-3,5-dienes are dependent upon the reaction conditions. Aqueous organic solvents and the gradual addition of peracid favour the formation of 6 -hydroxy-4-en-3-one, but when an excess of peracid is added in one portion the product, obtainable in high yield, is the unsaturated aldehyde-ester (393) which has also been obtained (as ethyl ester) by photochemical oxidation of the oxathian (394) followed by a reductive desulphuration. In non-polar solvents a 1 1 adduct (395) is formed between m-chloroperbenzoic acid and 3-acetoxy-3,5-dienes which is sufficiently stable (in the presence of a 17-ketone function) to be isolated and acetylated to the 6 -acetate or oxidised by chromium trioxide in pyridine to the b-ketone. ... 

C13H21NO7 acetic acid l-[bis-(2-acetoxy-ethyl)-carbamoylj-ethyl ester 6974-34-1... 

C8H14O5 acetic acid 2-(2-acetoxy-ethoxy)-ethyl ester 628-68-2... 

An all-trons structure was assigned to poly(endo,endo-N,N-(norborn-5-ene-2,3-dicarbimido)-L-valine ethyl ester) (Scheme 8.11). Finally, Wagener et al. published details of the formal synthesis of poly(ethylene-co-vinyl alcohol), poly(ethylene-co-vinyl acetate), poly (ethylene-co-methylacrylate) and poly(ethylene-co-acrylic acid) copolymers, obtained via the ROMP of cyclooctene with hydroxy-, acetoxy-, methoxy-carbonyl and carboxylate-functionahzed cyclooctenes, followed by hydrogenation... 

The Glaxo synthesis of zanamivir (2) started with the esterification of commercially available A-acetyl-neuraminic acid (88) with methanolic HCl to give the methyl ester as shown in Scheme 7.14 (Chandler and Weir, 1993 Chandler et ah, 1995 Patel, 1994 Weir et al., 1994). Global acetylation of all the hydroxyl groups with acetic anhydride in pyridine with catalysis by 4-(dimethylamino)pyridine (DMAP) led to the penta-acetoxy compound 89. Treatment of 89 with trimethylsilyl triflate in ethyl acetate at 52°C introduced the oxazoline as well as the 2,3-double bond to provide 86. Addition of trimethysilyl azide to the activated allylic oxazoline group led to the stereoselective introduction of azide at the C-4 position to afford 83 as in Scheme 7.13. 

The reaction between ethyl Hthiopropiolate and the N-acylpyridinium salt formed by reaction of 4-methoxy-3-methyl-5-(triisopropylsilyl)pyridine 2363 with (+)-frafis-2-(a-cumyl)-cyclohexyl chloroformate (TCC chloro-formate) was the starting point in the synthesis of (-l-)-aUopumihotoxin 267A (1718) by Comins et al. (Scheme 301). The dihydropyridone product (—)- 2364 was obtained diastereoselectively (>96%) before hydrogenation to the saturated ester (+)-2365. However, some epimerization of the methyl substituent was apparent after cleavage of the TCC carbamate with lithium methoxide and cyclization to the indolizidinone (—)-2366 (dr 8 1). Acetoxylation at C-8 with lead tetraacetate was stereoselective, and introduced the acetate from the axial direction, possibly by stereoelec-tronicaUy-controUed intramolecular transfer of acetate from a lead—enol intermediate. The acetoxy product (—)-2367 was protodesilylated with formic acid, after which a one-pot tandem reduction with K-Selectride followed by hthium aluminum hydride gave diol (- -)-2368 with complete... 

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