Enolesters esters

Markownikoff addition. 2-Methylpent-l-ene allowed to react with tertAmiyl hydroperoxide and mercuric acetate with initial cooling and shaking, after 2 hrs. the volatiles removed by distillation in vacuo, and the residue digested repeatedly with coned, aq. NaCl -> l-diloromercuri-2-tert-butylperoxy-2-methylpentane. Y 19%. F. e., also hydroperoxymercuration with H2 2 s. E. Schmitz, A. Riedie, and O. Brede, J. pr. 312, 30 (1970) a-alkoxyketones from enolesters s. ibid. 312, 43 peroxy- and methoxy-mercuration of a,i -unsatd. ketones and esters s. A. J. Bloodworth and R. J. Bunce, Soc. (C) 1971, 1453. 

Selective reduction. A soln. of borane in tetrahydrofuran added dropwise at -18 during 19 min. to a mixture of adipic acid monoethyl ester and tetrahydrofuran, stirred and allowed to warm to room temp, during 16 hrs. -> ethyl 6-hydroxy-hexanoate. Y 75-88%. - Other functional groups such as cyano, halogeno, keto, or nitro, are likewise retained during this highly convenient reduction. F. e., also reduction of sterically hindered acids, s. N. M. Yoon, H. C. Brown et al., J. Org. Chem. 38, 2786 (1973) 2-aminoalcohols from a-aminocarboxylic acids s. M. L. Anhoury et al., Soc. Perkin 11974,191 via reduction with aq. NaBH of enolesters obtained from the acids and N-ethyl-5-phenylisoxazolium 3 -sulfonate (s. Synth. Meth. 16, 448) s. P. L. Hall and R. B. Perfetti, J. Org. Chem. 39, 111 (1974). 

Acylketenes l-(AIkoxy)enolethers a-Alkoxymethyleneketones Carboxylic acid isopropenyl esters Enolesters Enollactols Enollactones a, p-Ethyleneacetals a,0-Ethylenelactones a-Hydroxymethyleneketones 3-Keto-l, 2-en-l-olethers 3-Keto-l,2-en-l-ols a-Oxidoalcohols a,P-Oxidoketones Vinyl esters... 

Oxalic ester synthesis—Enolesters from ketones. 6 g. dl-zl5,14-3.Ethylenedioxy-lly ,18-oxido-16-oxo-18-tetrahydropyranyloxyandrostadiene and dimethyl oxalate in benzene added dropwise to NaH in oil (Metal Hydrides, Inc., Beverly, Mass., USA) and benzene, stirred 48 hrs. at 30° in a slow Ng-stream, the crude product dissolved in benzene, and allowed to stand at room temp, overnight with acetic anhydride and pyridine 6.61 g. methyl dl-J5,14,17(20)-3-ethylene-dioxy-1 ly, 18- oxid o-16- oxo-18- tetrahydropyranyloxy - 20 - acetoxypregnatrien-21-ate, 6 g. suspended in an ice-cold 10 1 mixture of morpholine and water, stirred 3-4 hrs. until a clear soln. results, allowed to stand 24 hrs. at ca. 10°, evaporated almost to dryness at 35-40°/0.05 mm., a mixture of benzene and ether then pyridine added, ice-cooled, acetic anhydride added, and allowed to stand 24 hrs. at room temp. 5.55 g. dl-j5,14,17(20)-3-ethylenedioxy-ll, 18-oxido-16-oxo-18-tetrahydropyranyloxy-20-acetoxypregnatrien-21-ic acid morpholide.—Morpholine is preferred to other sec. amines because of its good solvent properties (cf. Synth. Meth. lA, 87). Use of anhydrous amines caused decomposition. K. Heus-ler, P. Wieland, and A. Wettstein, Helv. A2, 1586 (1959). 

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