4-Oxoheptanedioic acid

Recently, Porter et al. (1986b, 1988) have reported the synthesis of both meso- and ( )-forms of a series of two-chain carbonyl diacids made by joining two pentadecanoic acid units by a carbonyl group at the 3,3, 6,6, 9,9 and 12,12 positions, 3,5-didodecyl-4-oxoheptanedioic acid (C-15 3,3 ), 6,8-dinonyl-7-oxotridecanedioic acid (C-15 6,6 ), 9,11-dihexyl-10-oxononadecanedioic acid (C-15 9,9 ) and 12,14-dipropyl-13-oxopentacosanedioic acid (C-15 12,12 ), respectively. The diacids were used to probe further the question of stereochemical preference in two-chain amphiphiles. The method used for examining the diastereomeric preference was equilibration by base-catalyzed epimerization in homogeneous, bilayer and micellar media. This method allows for stereoselection based on hydrophobic/hydrophilic considerations rather than classic steric size effects. 

Thus, conversion of 1-ethoxy-1-(trimethylsiloxy)cyclopropane under an atmosphere of carbon monoxide with a palladium catalyst gives 4-oxoheptanedioic acids. " " Using an optically active cyclopropane precursor under the same conditions gives a single diastereomeric product without racemization. 

Yeast reductions resulting in 6-pentyltetrahydro- or 6-heptyltetrahydro-2//-pyran-2-onc in optically pure form have been sealed up in industry to batches using 3 tons of baker s yeast173. An interesting example of 4-oxo acid reduction is the reaction of the methyl, ethyl, propyl and butyl monoesters of 4-oxoheptanedioic acid. These compounds, obtained by microbial hydrolysis of the symmetrical y-keto diesters with Pseudomonas dimimta, are reduced by baker s yeast in moderate yields of 25 54% but in enantiomerically pure form175. 

Di(4-hydroxyphenyl)-1,6-diazaspiro[4.4]nonane-2,7-dione is prepared from l,6-dioxaspiro[4.4]nonane-2,7-dione and p-aminophenol, and more basically by the reaction of p-aminophenol and 4-oxoheptanedioic acid. The reaction scheme is shown in Figure 8.4. 

Diethyl 3-oxoheptanedioate, for example, is clearly derived from giutaryl and acetic acid synthons (e.g. acetoacetic ester M. Guha, 1973 disconnection 1). Disconnection 2 leads to acrylic and acetoacetic esters as reagents. The dianion of acetoacetic ester could, in prin-ciple,be used as described for acetylacetone (p. 9f.), but the reaction with acrylic ester would inevitably yield by-products from aldol-type side-reactions. 

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