Carboxylic startg

Red lead oxide added portionwise at 50-55° to a stirred soln. of ethyl 5-tetra-hydroxybutyl-2-propylfuran-3-carboxylate in aq. 50%-acetic acid and benzene so that decoloration occurs before the next portion is added ethyl 5-formyl-2-propylfuran-3-carboxylate (startg. m. f. 484). Y 80-85%. F. e. s. R. E. Rosen-kranz et al., Helv. 46, 1259 (1963). 

Startg. cyanophosphonic ester treated slowly with satd. KCN-soln. so that the temp, does not rise while the pH reaches 12 -> phosphoric ester (Y 94%) refluxed 12 hrs. in coned. HCl -> a-hydroxyundecanoic acid (Y 93%). - This is part of a synthesis of a-hydroxycarboxylic acids from carboxylic acid chlorides with addition of 1 C-atom. F. e. s. Y. Okamoto, T. Nitta, and H. Sakurai, Kogyo Kagaku Zasshi 71, 187 (1968) C. A. 69, 35342. 

A soln. of 10,ll-dihydrodibenzothiepine-10,ll-dione monoxime in coned. HCl-ethanol refluxed 3 hrs. -> ethyl thioxanthene-9-carboxylate. Y 71.4%. Also from other startg. m. and limitations s. A. Luttringhaus and G. Creutzburg, Ang. Ch. 80, 115 (1968). 

A soln. of 5.0 g. ethyl 8/, 8a/ -dimethyl-l-oxo-l,2,3,4,6,7,8,8a-octahydro-2-naph-thoate in hexamethylphosphoramide added at 5° under Ng to a stirred mixture of a 60%-dispersion ofNaHin mineral oil and hexamethylphosphoramide, stirring continued 1 hr. at room temp., cooled to 5°, 1.93 g. chloromethyl methyl ether added, and stirred 2 hrs. at room temp. 5.7 g. crude methoxymethyl enol ether dissolved in ether, added rapidly with Dry Ice-cooling under argon to a stirred dark blue soln. of Li in anhydrous NH3, and stirring continued 12 min. at -33°, the b. p. of liq. NHg 2.85 g. ethyl 8/, 8ai -dimethyl-l,2,3,4,6,7,8,8a-octahydro-2j -naphthoate. Overall Y 60%. - 0-Alkylation of the startg. -keto esters occurs under the above conditions to the complete exclusion of the C-alkylated isomer. The subsequent reduction gives the less stable axial isomer. R. M. Coates and J. E. Shaw, J. Org. Chem. 35, 2597 (1970) f. e. s. ibid. 35, 2601 carboxylic acids, also from a,/ -ethylenecarboxylic acids, cf. ibid. 36, 1151 (1971). 

Enamines from thioimino-esters. - Vinylogous carboxylic acid amides. Startg. thioimino-ester dissolved in triethyl phosphite, and warmed 20 hrs. at 60° under Ng -> product. 

Diethylaminoethyl 1-phenyl-2,3-dimethyl-5-pyrazolone-4-carboxylate and 7-hydroxyethyltheophylline stirred 8 hrs. at 200-220° in vacuo -> 7-theophylIin-ethyl 1-phenyl-2,3-dimethyl-5-pyrazolone-4-carboxylate. Y 73%. — The startg. ester-base acts as its own basic catalyst. F. e. s. T. Eckert, Arch. Pharm. 298, 337 (1965). 

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