Sodium ethanolate

The Claisen condensation is initiated by deprotonation of an ester molecule by sodium ethanolate to give a carbanion that is stabilized, mostly by resonance, as an enolate. This carbanion makes a nucleophilic attack at the partially positively charged carbon atom of the e.ster group, leading to the formation of a C-C bond and the elimination ofan ethanolate ion, This Claisen condensation only proceeds in strongly basic conditions with a pH of about 14. 

Reduction. Quinoline may be reduced rather selectively, depending on the reaction conditions. Raney nickel at 70—100°C and 6—7 MPa (60—70 atm) results in a 70% yield of 1,2,3,4-tetrahydroquinoline (32). Temperatures of 210—270°C produce only a slightly lower yield of decahydroquinoline [2051-28-7]. Catalytic reduction with platinum oxide in strongly acidic solution at ambient temperature and moderate pressure also gives a 70% yield of 5,6,7,8-tetrahydroquinoline [10500-57-9] (33). Further reduction of this material with sodium—ethanol produces 90% of /ra/ j -decahydroquinoline [767-92-0] (34). Reductions of the quinoline heterocycHc ring accompanied by alkylation have been reported (35). Yields vary widely sodium borohydride—acetic acid gives 17% of l,2,3,4-tetrahydro-l-(trifluoromethyl)quinoline [57928-03-7] and 79% of 1,2,3,4-tetrahydro-l-isopropylquinoline [21863-25-2]. This latter compound is obtained in the presence of acetone the use of cyanoborohydride reduces the pyridine ring without alkylation. 

Simple a-fluorosulfides are reduced to the fluoroalkanes by sodium-ethanol [9J (equation 75). Clean conversion of bis(trifluoromethyl) diiulfide to trifluoromethyl mercaptan is accomplished with hydrogen sulfide and ultraviolet irradiation (941 (equation 76). Perfluoroalkanesulfonyl fluondes are converted to the sulfmate salts by hydrazine [95] (equauon 77)... 

On treatment with sodium ethanolate or aqueous ethanolic KOH, 2,5-diaza-1,6-dioxa-6<2-tellurapentalenes 97 eliminates a tellurium atom to give l,2,3-triketone... 

Electrochemical reductions of camphor oxime (R = Me) and norcamphor oxime (R = H) at a mercury cathode proceed with a high degree of diastereoselectivity (equation 3) . The products are in fact of opposite stereochemistry to those formed in dissolving metal (sodium-ethanol) reductions of the oximes. 

Treatment of Cg Clg with sodium methanolate or sodium ethanolate under reflux respectively at room temperature for some days leads to C5q(OR)5C1 in moderate yields [83]. A by-product of the reaction with EtO is l,4-(EtO)2CgQ, showing that... 

C9H6O2, Mr 146.15, pi.33kPa 153.9 °C, df 0.935, occurs widely in nature and determines, for example, the odor of woodruff. It forms white crystals mp 70.6 °C) with a haylike, spicy odor. When treated with dilute alkali, coumarin is hydrolyzed to the corresponding coumarinic acid salt (cw-2-hydroxycinnamic acid). Heating with concentrated alkali or with sodium ethanolate in ethanol results in the formation of o-coumaric acid salts (trans-2-hydroxycinnamic acid). 3,4-Dihydro-coumarin is obtained by catalytic hydrogenation, for example, with Raney nickel... 

Quinoline may be reduced rather selectively, depending on the reaction conditions. Catalytic reduction with platinum oxide in strongly acidic solution at ambient temperature and moderate pressure gives a 70% yield of 5,6,7,8-tetrahydroquinoline. Further reduction of this material with sodium-ethanol produces 90% of fratrr-decahydroquinoline. 

Alkylene CCs have been prepared through the transesterification of appropriate glycols with dialkyl carbonates (usually diethyl or dimethyl carbonate) in the presence of a suitable catalyst. One of the first such examples was the synthesis of six-membered CCs by the transesterification of propane-1,3-diols with DEC catalyzed by sodium ethanolate (Equation 7.31) [289], The reaction was carried out at temperatures between 293 and 333 K, and a conversion yield of 40% was obtained. 

Desulfonylation of a-sulfonylacetates. Desulfonylation of these substrates is not satisfactory by the usual methods (Zn-HOAc, Raney Ni-C,H5OH, sodium amalgam), but can be conducted in 70-75% yield with sodium-ethanol in THF (modified Bouveault-Blanc reduction). The substrates (2) are obtained by Wolff rearrangement of a-acyl-a-benzyl-sulfonyldiazomethanes (1).1... 

Sodium 0,0-diethyl phosphorotelluroate, 485 Sodium dithionite, 485 486 Sodium-Ethanol, 472 Sodium-Hexamethylphosphoramide, 473 Sodium hydride-Sodium /-amyl oxide-Zinc chloride, 486... 

DESULFONYLATION Lithium-Ethylamine. Sodium-Ethanol. Sodium amalgam. Tetrakis(tnphenylphosphine)palladium. DESULFURATION ... 

Reactions for Spillage and Waste Disposal NaOCH,CH + HC1 NaCl + CHjCH3OH sodium ethanol chloride... 

Hydrazobenzene Diethyl-n-butyl malonate Sodium Ethanol... 

Submission of 1,6-naphthyridine to sodium/ethanol reduction followed by hydrogenation over platinum oxide afforded trawi-decahydro-1,6-naphthyridine (6) in 65% yield (for details, see original).47... 

A synthesis of the pear ester worked out in our laboratory uses the (Z)- and the ( )-stereoselective Wittig olefination for the generation of the two double bonds in the molecule 232165). Reaction of 2-ethoxyvinyl-triphenylphosphonium bromide 234 with one equivalent sodium ethanolate yields 2,2-ethoxyethylene-triphenyl-phosphorane 235166,167). (Z)-Stereoselective olefination of 235 with hexanal 236... 

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