5- Methoxypentanoic acid

Phenyl-5-methoxypentanoic acid, A 26.7 3-(o-Methoxyphenyl)pentanoic acid, A 26.11 Oudenone, Y 5.10 Coronafacic acid, Y"21.7, Y"21.8 Tricyclo[5.2.1.O ]decane-3,10-dione 10-ethylene ketal, X"12.4... 

As with the acetoacetic ester synthesis, we have already encountered all the important chemistry of the malonic ester synthesis, although not in this particular pattern. Let us illustrate this synthesis by choosing 5-methoxypentanoic acid as a target molecule. The two carbons shown in color are provided by diethyl malonate. The remaining three carbons and the methoxy group represent the —R group of a monosubstituted acetic acid. 

Heating the j8-dicarboxylic add slightly above its melting point brings about decarboxylation and gives 5-methoxypentanoic acid. 

HO-5, azide substitution, and hydrogenolysis led to the precursors of 58 and 59, respectively. Also, the (S)-5-amino-5-deoxy-4-methoxypentanoic acid (60) was prepared from D-ribono-1,4-lactone (via its 2-bulenolide) and from L-glutamic acid, as depicted in Scheme 14.53 Compound 60 was N-protected and carboxylate activated to give 6L The... 

Orgueira H.A., Bueno M., Runes J.L., Varela O., Galbis J.A., Synthesis and characterization of chiral polyamides derived from glycine and (S)-5-amino-4-methoxypentanoic acid, J. Polym. Sci Part A Polym. Chem., 36, 1998, 2741-2748. 

The synthesis of succinic acid derivatives, /3-alkoxy esters, and a,j3-unsaturated esters from olefins by palladium catalyzed carbonylation reactions in alcohol have been reported (24, 25, 26, 27), but full experimental details of the syntheses are incomplete and in most cases the yields of yS-alkoxy ester and diester products are low. A similar reaction employing stoichiometric amounts of palladium (II) has also been reported (28). In order to explore the scope of this reaction for the syntheses of yS-alkoxy esters and succinic acid derivatives, representative cyclic and acyclic olefins were carbonylated under these same conditions (Table I). The reactions were carried out in methanol at room temperature using catalytic amounts of palladium (II) chloride and stoichiometric amounts of copper (II) chloride under 2 atm of carbon monoxide. The methoxypalladation reaction of 1-pentene affords a good conversion (55% ) of olefin to methyl 3-methoxyhexanoate, the product of Markov-nikov addition. In the carbonylation of other 1-olefins, f3-methoxy methyl esters were obtained in high yields however, substitution of a methyl group on the double bond reduced the yield of ester markedly. For example, the carbonylation of 2-methyl-l-butene afforded < 10% yield of methyl 3-methyl-3-methoxypentanoate. This suggests that unsubstituted 1-olefins may be preferentially carbonylated in the presence of substituted 1-olefins or internal olefins. The reactivities of the olefins fall in the order RCH =CHo ]> ci -RCH=CHR > trans-RCH =CHR >... 

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