Sodium hydride epoxides

Substitution of an additional nitrogen atom onto the three-carbon side chain also serves to suppress tranquilizing activity at the expense of antispasmodic activity. Reaction of phenothia zine with epichlorohydrin by means of sodium hydride gives the epoxide 121. It should be noted that, even if initial attack in this reaction is on the epoxide, the alkoxide ion that would result from this nucleophilic addition can readily displace the adjacent chlorine to give the observed product. Opening of the oxirane with dimethylamine proceeds at the terminal position to afford the amino alcohol, 122. The amino alcohol is then converted to the halide (123). A displacement reaction with dimethylamine gives aminopromazine (124). ... 

The hydrogeh atom bound to the amide nitrogen in 15 is rather acidic and it can be easily removed as a proton in the presence of some competent base. Naturally, such an event would afford a delocalized anion, a nucleophilic species, which could attack the proximal epoxide at position 16 in an intramolecular fashion to give the desired azabicyclo[3.2.1]octanol framework. In the event, when a solution of 15 in benzene is treated with sodium hydride at 100 °C, the processes just outlined do in fact take place and intermediate 14 is obtained after hydrolytic cleavage of the trifluoroacetyl group with potassium hydroxide. The formation of azabi-cyclo[3.2.1]octanol 14 in an overall yield of 43% from enone 16 underscores the efficiency of Overman s route to this heavily functionalized bicycle. 

Solladie-Cavallo s group used Eliel s oxathiane 1 (derived from pulegone) in asymmetric epoxidation (Scheme 1.3) [1]. This sulfide was initially benzylated to form a single diastereomer of the sulfonium salt 2. Epoxidation was then carried out at low temperature with the aid of sodium hydride to furnish diaryl epoxides 3 with high enantioselectivities, and with recovery of the chiral sulfide 1. 

A synthetically useful diastereoselectivity (90% dc) was observed with the addition of methyl-magnesium bromide to a-epoxy aldehyde 25 in the presence of titanium(IV) chloride60. After treatment of the crude product with sodium hydride, the yy -epoxy alcohol 26 was obtained in 40% yield. The yyn-product corresponds to a chelation-controlled attack of 25 by the nucleophile. Isolation of compound 28, however, reveals that the addition reaction proceeds via a regioselective ring-opening of the epoxide, which affords the titanium-complexed chloro-hydrin 27. Chelation-controlled attack of 27 by the nucleophile leads to the -syn-diastereomer 28, which is converted to the epoxy alcohol 26 by treatment with sodium hydride. 

Key steps, as shown in Scheme 4-15, involve the formation of a urethane intermediate 37 by treating epoxide 36 with methyl isocyanate in the presence of sodium hydride. Intramolecular A-nucleophilic ring opening of oxirane affords oxazolidine 38. Subsequent treatment furnishes product 34. 

Cyclododecene may be prepared from 1,5,9-cyclododecatriene by the catalytic reduction with Raney nickel and hydrogen diluted with nitrogen, with nickel sulfide on alumina, with cobalt, iron, or nickel in the presence of thiophene, with palladium on charcoal, with palladimn chloride in the presence of water, with palladium on barium sulfate, with cobalt acetate in the presence of cobalt carbonyl, and with cobalt carbonyl and tri- -butyl phosphine. It may also be obtained from the triene by reduction with lithium and ethylamine, by disproportionation, - by epoxidation followed by isomerization to a ketone and WoliT-Kishner reduction, and from cyclododecanone by the reaction of its hydrazone with sodium hydride. ... 

Arene(tricarbonyl)chromium complexes, 19 Nickel boride, 197 to trans-alkenes Chromium(II) sulfate, 84 of anhydrides to lactones Tetrachlorotris[bis(l,4-diphenyl-phosphine)butane]diruthenium, 288 of aromatic rings Palladium catalysts, 230 Raney nickel, 265 Sodium borohydride-1,3-Dicyano-benzene, 279 of aryl halides to arenes Palladium on carbon, 230 of benzyl ethers to alcohols Palladium catalysts, 230 of carboxylic acids to aldehydes Vilsmeier reagent, 341 of epoxides to alcohols Samarium(II) iodide, 270 Sodium hydride-Sodium /-amyloxide-Nickel(II) chloride, 281 Sodium hydride-Sodium /-amyloxide-Zinc chloride, 281 of esters to alcohols Sodium borohydride, 278 of imines and related compounds Arene(tricarbonyl)chromium complexes, 19... 

From epoxides by reduction Samarium(II) iodide, 270 Sodium hydride-Sodium /-amyloxide-Nickel(II) chloride, 281 Sodium hydride-Sodium /-amyloxide-Zinc chloride, 281... 

The benzylidene and p-chlorobenzyIidene triphenylarsorane ylides, when generated from sodium ethoxide in ethanol, react with a series of substituted benzaldehydes to give epoxides regardless of the nature of substituents present on the aromatic aldehyde (55, 97). However, the same ylides generated from sodium hydride in benzene (59), reacted with a series of aldehydes to give olefins. These observations clearly show that the base and solvent, in addition to the nature of substituent present on the ylidic carbanion, play an important role in dictating the exact path of the reaction. 

The l,3-dioxane-2-ethanol (2 ml) was added dropwise to sodium hydride (396 mg of 60% dispersion, 10 mmol) at RT under argon. When the effervescence had ceased, l l,N,N, N -tetramethylenediamine (TMEDA) (1 ml) was added, the mixture stirred for a further 4 h and then a solution of the epoxide (396 mg, 1.0 mmol) in TMEDA (1.0 ml) was added dropwise. The mixture was stirred at 100-110°C for 3 days and then allowed to cool to RT. Water was added and, after 5 min the mixture extracted with ether. The extract was washed with water and the aqueous phase reextracted with ether. The combined organic extracts were dried (MgS04) and evaporated in vacuum column chromatography (4% MeOH-10% ether-86% petrol) of the residue afforded [2(R)]-L-3-0-Benzyl-4,5-0-isopropylidene-6-0-[2-(5,5-dimethyl-l,3-dioxan-2-yl)ethyl]-2-0-(l-phenylethyl)-muco-inositol (176 mg, 31%), [a]D20 +63.4° (c 1.4, CHCI3) and [S(R)]-D-4-0-Benzyl-2,3-0-isopropylidene-6-0-[2-(5,5-dimethyl-l,3-dioxan-2-yl)ethyl]-5-0-(phenylethyl)-myo-inositol (273 mg, 48%), mp 108°-110°C, [a]D20+ 29.3° (c 0.76, CHCI3) as a thick oil and a white solid respectively, and starting epoxide (65 mg, 16%). 

N-Alkylation—Secondary Mannich bases can give the corresponding tertiary derivatives by treatment with particular alkylation agents, such as epoxides (affording P-ami-noalcohols) and acrylic derivatives. Tertiary Mannich bases, mostly, are submitted to N-alkylation in order to produce stable quaternary ammonium salts to be subsequently subjected to deamination (Sec. A.2). However, different quaternary ammonium byproducts can be readily given by the reaction. " For instance, a base-catalyzed rearrangement is afforded by allyl ammonium salts 365 (Fig. 144), obtained by N-alkylation of acetylenic Mannich bases with ally] halides. " In the presence of sodium hydride, the compounds 365 yield a wide range of 3-amino-5-hexen-l-yne derivatives 366. 

Red-Al [sodium bis(2-methoxyethoxy)aluminium hydride] reduces aliphatic halides and aromatic halides to hydrocarbons. Reductive dehalogenation of alkyl halides is most commonly carried out with super hydride. Epoxide ring can also be opened by super hydride. 

Oxiranes. A recent, general synthesis of epoxides involves a -sulfenylation of a ketone, reduction of the C=0 group to CHOH, methylation to give a fi-hydtoxy dimethylsulfonium iodide, and, finally, cyclization with potassium t-butoxide (or sodium hydride) in DMSO. cw-Epoxides are formed exclusively. 

Tosylhydrazone 54 also served as a branch point to start a divergent route toward authentic laukarlaol (Scheme 36) [69]. Thus, the treatment of 54 with sodium hydride gave diene 55, which underwent selective epoxidation at the a face of the double bond. A nuclear Overhauser effect observed between... 

Like S,S-Dimethyl-N-(p-toluenesulfonyl)sulfoximine and (dimethylamino)dimethyloxosulfonium tetrafluoroborate, the 7Y-tosylsulfilimine (1) reacts as a methylene transfer reagent, converting aldehydes and ketones to epoxides (eq 3). Thus (1) is heated at 80-90 °C for 0.5 h in DMSO in the presence of Sodium Hydride, and the resulting anion is allowed to react with carbonyl compounds to give 1-mono- and 1,1-disubstituted oxiranes in 46-56% yields. ... 

The system of sodium hydride, sodium alkoxide and metal salts developed by Caubere and his coworkers can selectively reduce epoxides to alcohols (Table 6). The regiochemistry of ring opening is con-... 

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