Oxirans 2-amino alcohol

Amines oxiranes amino alcohols aziridines diamines. 

Due to the abundance of epoxides, they are ideal precursors for the preparation of P-amino alcohols. In one case, ring-opening of 2-methyl-oxirane (18) with methylamine resulted in l-methylamino-propan-2-ol (19), which was transformed to 1,2-dimethyl-aziridine (20) in 30-35% yield using the Wenker protocol. Interestingly, l-amino-3-buten-2-ol sulfate ester (23) was prepared from l-amino-3-buten-2-ol (22, a product of ammonia ring-opening of vinyl epoxide 21) and chlorosulfonic acid. Treatment of sulfate ester 23 with NaOH then led to aziridine 24. ... 

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). ... 

By the extension of the above-mentioned stereoselective asymmetric addition of alkylithiums to other organolithium reagents such as lithium salts of methyl phenyl sulfide, 2-methylthiazoline, trialkylsilylacetylene, N-nitroso-dimethylamine, and acetonitrile, chiral oxiranes (95) U1), thiiranes (96) nl), acetylenic alcohols (98) 112), and amino alcohols (97) U1) were readily obtained. 

Organometallic compounds asymmetric catalysis, 11, 255 chiral auxiliaries, 266 enantioselectivity, 255 see also specific compounds Organozinc chemistry, 260 amino alcohols, 261, 355 chirality amplification, 273 efficiency origins, 273 ligand acceleration, 260 molecular structures, 276 reaction mechanism, 269 transition state models, 264 turnover-limiting step, 271 Orthohydroxylation, naphthol, 230 Osmium, olefin dihydroxylation, 150 Oxametallacycle intermediates, 150, 152 Oxazaborolidines, 134 Oxazoline, 356 Oxidation amines, 155 olefins, 137, 150 reduction, 5 sulfides, 155 Oxidative addition, 5 amine isomerization, 111 hydrogen molecule, 16 Oxidative dimerization, chiral phenols, 287 Oximes, borane reduction, 135 Oxindole alkylation, 338 Oxiranes, enantioselective synthesis, 137, 289, 326, 333, 349, 361 Oxonium polymerization, 332 Oxo process, 162 Oxovanadium complexes, 220 Oxygenation, C—H bonds, 149... 

A mixture of epoxides 483 obtained on oxidation of 482 with dimethyldioxirane, when exposed to ferric chloride provided, as the kinetically controlled product, the a-aldehyde 484, which without purification was reduced to the a-alcohol 485. The exclusive formation of 484 is believed to occur via the benzyl cation 486, generated by Lewis-acid opening of the oxirane ring, suffering a stereospecific kinetic 1,2-hydride shift The amino alcohol 487 obtained after sequential removal of O-benzyl and N-tosyl groups from 485, on treatment with triphenylphosphine and iodine in the presence of imidazole furnished the tetracyclic base 488, which was oxidised to the ketone 489. Trapping of the kinetically generated enolate of 489 as the silylether, followed by palladium diacetate oxidation yielded the enone 490. The derived... 

Catalytic amounts of tin(II) chloride have been found to give good yields (72-86%) of the trans-amino alcohols when oxiranes have been treated with aromatic amines in acetonitrile at room temperature.27 Only the reaction with styrene oxide was regiospe-ciflc with the amine adding to the benzylic carbon of the epoxide ring. 

The amount of catalyst (scandium trisdodecyl sulfate) and ligand, (14), in the ring opening of czT-1,2-disubstituted oxiranes with primary and secondary aromatic amines in water were varied to maximize the yields.33 In all but two cases, the reaction, under ideal conditions, yielded the j3-amino alcohols in >81% yield with enantioselectivity ... 

When the same conditions are applied to oxirane 5 azido alcohol 17 is formed this can be selectively reduced with triphenylphosphine to give amino alcohol 18 in good yield (Scheme 6.4.8 Eq. 2) [11, 25, 26], This compound and other, related, epoxides are a new approach to the chemistry of aminocarbasugars and their unsaturated analogs such as valienamine [27]. 

The standard preparation of 2-oxazolidinones is by treatment of /3-amino alcohols with phosgene or its synthetic equivalents ethyl chloroformate, dialkyl carbonates or even urea (equation 174). Isocyanates react with oxiranes in the presence of amines to yield 2-oxazolidinones (equation 175) (79LA200). The action of isocyanates on cyclic carbonates results in 2-oxazolidinones (equation 176) and photolysis of alkyl azidoformates affords oxazolidinones via intermediate nitrenes (equation 177). 

Hydroxide ions oxiranes glycols aziridines amino alcohols. 

Amino alcohols 127 are readily available from o-aminothiophenols and oxirane. They were further cyclized with phosgene or triphosgene to afford dibenzo[<7,g][l,6,3]oxathiazocin-6(777)-ones 128 in moderate to good yields (Scheme 32 <1997USP5621153>). 

In addition to the oxidative scission of 1,2-diols, the reaction can be extended to related 1,2-bifunc-tional compounds such as oxiranes, 1,2-dicarbonyl compounds, 2-hydroxy aldehydes, ketones and acids, a-amino alcohols, 1,2-diamines and also to polyols. LTA cleaves a-hydroxy acids much more readily than do periodates and both reagents oxidize 2-hydroxy aldehydes and 1,2-dicarbonyl compounds relatively slowly. Only periodic acid in water reacts with oxiranes via the corresponding diols. 

Nucleophiles, e.g. ammonia or amines, cause oxiranes to ring-open to give amino alcohols ... 

Amino alcohols, which are conveniently made from oxiranes with ammonia or amines, react with thionyl chloride to give chloroamines, which can be cyclized to aziridines by alkali hydroxide (Gabriel 1888). 

Dihydrooxazoles are prepared from y0-amino alcohols (from oxiranes and ammonia, see p 18) and carboxylic acids or carboxylic esters [75]. A -(2-Hydroxyalkyl)carboxylic acid amides can be isolated as intermediates and subsequently subjected to thermal cyclodehydration or to the action of H2SO4, SOCI2 or to other dehydrating agents ... 

The 1 1 complex formed between ZnCla and tetramethyl-2-tetrazene reacts with cyclo-octene and oxygen to give solely the oxiran, whereas with styrene the reaction goes further, the intermediate oxiran ring being opened regiospecifically to produce the amino-alcohol PhCH(OH)CH2NMe2. ... 

Nitrogen Source Synthesis of Amines. KHMDS has been exploited as a nitrogen source in a few systems. For instance, the ring opening of (trifluoromethyl)oxirane with KHMDS, followed by acidic hydrolysis produced the desired amino alcohol in 61% yield without any variation in the enantiomeric purity (eq 25). ... 

Amino-alcohol synthesis may also be achieved by the simple, classical addition of amines to oxiranes. However, even today such procedures are often limited by poorly nucleophilic amines, incompatibility of some epoxides with reaction conditions and poor regioselectivity of addition. It has been shown that compared to the use of Si02 or kl20-, the Na-exchanged Y-type zeolite resin ZCP-50 mediates such additions with consistently improved regio-... 

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