Diethyl formylsuccinate

The foregoing formula has been confirmed by the synthesis of pilosinine by Poljakova and V. A. and N. A. Preobrashenski, who followed the process used for the synthesis of pilocarpine and the allied alkaloids see p. 625), starting with diethyl formylsuccinate to produce pilosinie acid,... 

The condensation of diethyl formylsuccinate with amidines is an established p3mmidine synthesis (16, 714). Extended to 1-substituted biguanides, the reaction yields 2-guanidino-4-hydroxy-5-carbethoxy-methylpyrimidines as follows (684) ... 

The esters of maleic acid can be hydroformylated to obtain the formyl derivative 8. Adkins and Kresk reported the reaction of diethyl fumerate 7. In the presence of a cobalt catalyst at 150°C and a total pressure of 4 800 psi of carbon monoxide and hydrogen (2 1) CO Hi, the Oxo product, diethyl formylsuccinate 8 (R = Et), was formed in a 51% yield. The fate of the remaining material was not specified but it is believed to have mostly converted to diethyl succinate by hydrogenation (see below). 

Diethyl ethylsuccinate and ethyl formate added to a suspension of Na-methoxide prepared from Na and methanol in anhydrous toluene, kept 2 days at 10-15° diethyl a-ethyl-a -formylsuccinate (Y 90.2% based on startg. m. consumed) hydrogenated 3-4 hrs. at 110-120° with Raney-Ni in anhydrous alcohol at an initial pressure of 80-100 atm., the catalyst separated, the solvent distilled off, and the residue distilled at 10 mm ethyl a-ethylparaconate (mixture of racemic stereoisomers Y 96.8%). F. e. s. N. A. Preobrazhenskii et al., X. 30, 2250 (1960) G. A. 55, 9368a. 

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