Diethyl /-malate

Metal amalgams may be used for reduction of the keto groups in keto esters provided the medium does not cause hydrolysis of the ester. Because of that aluminum amalgam in ether is preferable to sodium amalgam in aqueous solutions. Diethyl oxalacetate was reduced to diethyl malate by sodium amalgam in 50% yield and with aluminum amalgam in 80% yield [148], Stereospecific reduction of a- and fi-keto esters to optically pure hydroxy esters was achieved by biochemical reduction in moderate to good yields. Saccharomyces cerevisiae converted methyl 2-keto-2-phenylacetate to methyl... 

Kugelrohr distillation does not separate the starting material, diethyl malate. Distillation through a 30-cm Vigreux column (silvered vacuum jacket) leads to loss of material (only 40% yield, dlastereomer ratio 90 10, free of starting material). 

The use of Al(Hg) in ether for the reduction of alkali-sensitive compounds may give higher yield than Na(Hg) thus, diethyl oxaloacetate is reduced to diethyl malate by Al(Hg) in 70-80% yield, whereas Na(Hg) gives about 50% yield [78]. 

Malathion, the well-known insecticide, and the much more toxic isomalathion, (83) have one and two chiral centres, respectively. Chiral forms of the former have been prepared from the appropriate diethyl malate by sequential reaction with trifluoromethanesulphonic anhydride and sodium 0,0-dimethyl phosphorodithioate thus, for example, (-)-malic acid yields (/f )-malathion (84). Monodemethylation of the malathion enantiomers with strychnine, and methylation (dimethyl sulphate) of the... 

Triol 370 can also be prepared by reduction of EE-protected dimethyl malate 9a [14,15] or diethyl malate 9b [16] to give (5)-2-(l-ethoxyethoxy)-1,4-butanediol (371) in high yield. Deprotection under acidic conditions then furnishes 370 (Scheme 49). Cyclization of 370 (obtained by this route) under acidic conditions results in the formation of ( S)-( + )-3-... 

Both enantiomers of 4-iodo-1,2-epoxybutane are available from ( S)-malic acid as shown in Schemes 57 and 58. Reduction of THP-protected dimethyl or diethyl malate with lithium aluminum hydride gives diol 417. Immediate mesylation affords 418 in 65—70% overall yield [6,19]. Acidic hydrolysis of the THP ether furnishes the crystalline bis-mesylate 419, which upon mild base treatment cyclizes to epoxide 420 with retention of configuration. Treatment with sodium iodide gives (5)-( — )-4-iodo-1,2-epoxybutane (421). 

Transesterification of all esters with tetraethyltitanate affords diethyl (/ )-malate (897) (Scheme 131) [199]. 

The base forms a dianion on diethyl malate, in which one of the charges is on an alkoxide while the other charge is on a to one of the esters. 

Diethyl hydroxybutanedioate Diethyl 2-hydroxybutanedioate Diethyl 2-hydroxy-1,4-butanedioate. See Diethyl malate N,N-Diethyl-N-(P-hydroxyethyl) amine. See Diethylaminoethanol Diethylhydroxylamine CAS 3710-84-7 EINECS/ELINCS 223-055-4 Synonyms DEHA N,N-Diethylhydroxylamine Hydroxylamine, N,N-diethyl-Empirical C4H11NO Formula (C2Hs)2NOH... 

Diethyl hydroxysuccinate. See Diethyl malate Diethyliodoaluminum. See Diethylaluminum iodide... 

Diethyl malate. See Diethyl DL-malate Diethyl DL-malate... 

CAS 626-11-9 EINECS/ELINCS 210-930-0 Synonyms Diethyl malate Ethyl malate DL-Malic acid diethyl ester... 

Diacetyl tartaric acid esters of mono- and diglycerides Diethyl malate Dihydro-a-ionone Dihydrojasmone Ethyl cyclohexylacetate... 

Beeswax, white Beeswax, yellow Benzoic, acid Benzyl tiglate y-Bisabolene Brominated vegetable oil 3-Butylidenephthalide Butyloxepanone 3-Butylphthalide Calcium lactate Caramel Castor (Ricinus communis) oil Citronellyl isovalerate Citronellyloxy acetaldehyde p-Cresyl isovalerate p-Cresyl octanoate Crotonic acid p-Cyclocitral p-Damascenone 9-Decenal trans-4-Decenal Diacetyl tartaric acid esters of mono- and diglycerides Diethyl malate Difurfuryl disulfide Dihydroeugenol Dihydro-a-ionone Dihydrojasmone Diisobutyl ketone Diisopropyl disulfide 3,4-Dimethylcyclopentane-1,2-dione Dimethyl dicarbonate 2,5 Dimethyl-3-furanthiol p-a-Dimethylstyrene Diphenyl oxide Ethyl acetate... 

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