Synthesis of opsopyrroledicarboxylic acid

Conclusions Starting with the diethyl ester of 3-formyl-4-ketopimelic acid we synthesized opsopyrroledicarboxylic acid in three steps.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 481–483, February, 1977.We express our gratitude to S. F. MacDonald (Canada) for graciously supplying samples of (I) and (VI).     

Synthesis of pteroic acid

Conclusions Pteroic acid was synthesized by starting with 2-amino-4-hydroxy-5-nitro-6-chloropyrimidine, epichlorohydrin, and p-aminobenzoic acid.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2821–2823, December, 1976.We express our gratitude to L. Plante for supplying the sample of (I).     

Synthesis of berninamycinic acid

A short, efficient synthesis of berninamycinic acid (1) is described.     

Synthesis of orotic acid from maleuric acid

Summary The bromination of maleuric acid or its methyl ester, with subsequent alkaline treatment of the intermediate bromides, leads to the formation of orotic acid.The authors wish to thank B. V. Lopatin, I. S. Runge, and V. A. Shyapochnikov for making the spectral studies.     

Synthesis of aminoshikimic acid

5-amino-5-deoxyshikimic acid (aminoshikimic acid) was synthesized from glucose using recombinant Amycolatopsis mediterranei and also synthesized by a tandem, two-microbe route employing Bacillus pumilus and recombinant Escherichia coli.     

Synthesis of juniperonic acid

Synthesis of juniperonic acid [(all-Z)-5,11,14,17-eicosatetraenoic acid], has been achieved in eight steps and in 19% overall yield starting from eicosapentaenoic acid.     

Synthesis of saramycetic acid

The first reported synthesis of saramycetic acid, a degradation product of the complex thiopeptide antibiotic cyclothiazomycin, is achieved in nine steps and 11% overall yield from diethoxyacetonitrile by a strategy, which incorporates two Hantzsch thiazole syntheses using thioamides prepared from the corresponding nitriles without the use of gaseous H₂S. The synthetic material was transformed to methyl saramycetate, which had spectroscopic properties in excellent agreement with the literature data.     

Synthesis of thomasic acid

Thomasidioic acid (2) has been synthesized in two steps by oxidative phenol coupling of sinapic acid (6) to the dilactone (7) followed by acid-catalyzed rearrangement. The diol dibenzyl ether (15), derived from thomasidioic acid dimethyl ester (9) by benzylation followed by LAH reduction, was selectively oxidized to yield thomasic acid (1) after debenzylation and base hydrolysis.     

Synthesis of dichloroisoeverninic acid

3,5-Dichloro-4-hydroxy-2-methoxy-6-methyl-benzoic acid 1, the so-called dichloroisoeverninic acid, a food additive¹ resp. a constituent of the orthosomycin antibiotics avilamycin, curamycin, everninomycin, flambamycin and related derivatives,² is synthesized from methyl orsellinate 2 in five steps in 40% overall yield.     

Synthesis of dihydrosenecic acid

Summary The synthesis of the lactone of dihydrosenecic acid was described.     

Synthesis of glycyrrhetic acid derivatives

11-Deoxyglycyrrhetinic acid (DGA) (2) was produced by Clemmensen reduction of the C-11 carbonyl of 18β-glycyrrhetic acid (GA) (1). Four derivatives of GA and DGA (3a–3d) were synthesized. Their structures were elucidated using spectral data (IR, mass, ¹H, ¹³C NMR). __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 153–155, March–April, 2008.     

Synthesis of nitroxylcarbamidophosphoric acid amides

A method for obtaining new organophosphorus nitroxyls was developed based on Kirsanov's phosphazo reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1139–1141, May, 1990.     

Synthesis of labelled dihydroartemisinic acid

[15-¹³C²H₃]-Dihydroartemisinic acid (2a), [15-C²H₃]-dihydroartemisinic acid (2b) and [15-¹³CH₃]-dihydroartemisinic acid (2c) have been obtained in good yield and high isotopic enrichment by a reconstructive synthesis from artemisinin. These labelled compounds were designed to be used in biosynthetic experiments to determine the origins of artemisinin and other sesquiterpene natural products from Artemisia annua.     

Synthesis of an oxa-lipoic acid

The synthesis of an oxa-lipoic acid is reported here for the first time. We have achieved the synthesis of the title compound starting from commercially available acrolein using a Michael addition and Knoevenagel condensation as key reactions.