Dimethyl propanedioate

This procedure has been applied as a key step in the synthesis of ( + )-ramulosin. Using dimethyl 1,3-propanedioate or cyanoacetate under basic conditions (20 °C, sodium methoxide) trans-adducts are obtained preferentially (diastereomeric ratios 2.5-l0 1)264. 

In an analogous manner the enantiomeric unsaturated bicyclic lactam 11 was transformed via conjugate addition of dimethyl 1,3-propanedioate (sodium amide/hexamethylphosphoric triamide) and subsequent alkylation with (bromomethyl)benzene to give the dialkylated product 12 in 20% yield12. 

Dimethyl 1,3-propanedioate (dimethyl malonate) was obtained from Aldrich Chemical Company, Inc., and used as supplied. 

Dimethyl 1,3-Propanedioate Malonic acid, dimethyl ester (8) Pro-panedioic acid, dimethyl ester (9) (108-59-8)... 

Synonyms Dimethyl propanedioate Dimethyl 1,3-propanedioate Malonic acid, dimethyl ester Methyl malonate Propanedioic acid, dimethyl ester... 

Dimethyl-l-phenyl-3-pyrazolin-5-one, a299 Dimethyl propanedioate, d630... 

Dimethyl phosphite, d541 Dimethyl pimelate, d530 Dimethyl propanedioate, d545... 

A mass spectrum is a two-dimensional graph. The m/z ratios of ions are shown on the abscissa axis and the relative abundances are shown on the ordinate axis. Figure 9.66 shows the mass spectrum of dimethyl propanedioate in El. The largest (base) peak of the spectrum (m/z 101 on Figure 9.66) is used as a reference for the relative abundances. The abundances of the other ions are expressed as percentages of the base peak. 

In El, the point is generally not to interpret all the ions present in the spectrum. The ions are so numerous that interpretation would be long and tedious. The point is to search for the structures of the most abundant and most specific ions. In the first approximation, we consider that the higher the m/z ratio of an ion, the more it is specific. If one considered, for example, the spectrum of dimethyl propanedioate... 

FIGURE 9.66 Electron ionization mass spectrum of dimethyl propanedioate. 

C7H12 04 2,2-dimethyl-propanedioic acid dimethyl ester 6065-... 

Acetamido-2-(7-chloroindol-3-ylmethyl)propanedioic acid dimethyl ester[6]... 

A solution of 1.18 g (7 mmol) 4-acetoxy-5,5-dimethyl-2-eyclopcnlonone and 1.13 g (7.1 mmol) of diethyl 1,3-propanedioate in 0.8 mL of ethanol is added to a solution of 40 mg (1.7 mmol) of sodium in 4 mL of ethanol and stirred for 0.5 h at 25 JC. The mixture is acidified with 1 mL of acetic acid and poured into 10 mL of water. The resulting mixture is extracted three times with 10 mL of diethyl ether. The combined ether layers are washed with 10 mL of 5% aq NaHC03,10 mL of brine and dried Over Na,S04. Evaporation of the solvent followed by chromatography (silica gel, henzene/ethyl acetate 30 1) affords the crude product which was recrystallized from hexane yield 478 mg (21 %) mp 65-66°C. 

Dimethyl (1, R,2 R,5,R)-2-(2 -isopropenyl-5 -methylcyclohex-1 -yl)-propane-1,3-dioate Propanedioic acid, [5-methyl-2-(1-methylethenyl)cyclohexyl]-, dimethyl ester, [1R-(1a,2p,5o)]- (12) (106431-81-6)... 

Dimethyl mesoxolate Propanedioic acid, oxo-, dimethyl ester (9) (3298-40-6) Dimethyl benzalmalonate Malonic add, benzylidene-, dimethyl ester (8) Propanedioic add, (phenylmethylene)-, dimethyl ester (9) (6626-84-2) Dimethyl sulfide Methyl suflide (8) Methane, thiobis- (9) (75-18-3)... 

Propanedioic acid, diethyl ester (105-53-3), 66, 179 Propanedioic acid, (methoxyraethylene)-, dimethyl ester, 65, 98 Propanedioic acid, (3-methyl-2-butenyl)-, dimethyl ester ... 

A solution of 2-chlorophenylhydrazine hydrochloride (89.5 g, 0.50 mol) in water (800 ml) was neutralized with 1 N NaOH and extracted with benzene (800 ml). The solution was dried (MgS04) and filtered. Acetic acid (10.7 ml) and dimethyl 2-acetamido-2-(3-oxopropyl)propanedioate (122.5 g, 0.50 mol) were dissolved in benzene (200 ml) and added. This mixture was stirred for 1 h at 50°C and then kept at 4°C for 2 days. The hydrazone precipitated. Additional product was recovered by concentration of the filtrate to about... 

Aceiamido 2-(7-chloromdoh3 ylmethyl)propanedioic acid dimethyl ester 62... 

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