Synthesis of 6α,7β-Di-Hydroxyvouacapan-17β-Oic acid derivatives part III: synthesis, ¹H- and 13C-NMR of amide derivatives¹

Journal of the Brazilian Chemical Society

Piló-Veloso, Dorila¹  Stefani, Guglielmo Marconi¹  Ferreira-Alves, Dalton Luiz¹  Maltha, Célia Regina Álvares¹  ICEx¹ 

关键词: 6α;    7β-di-hydroxyvouacapan-17β-oic acid;    furane-diterpene;    amide;    1H- and 13C-NMR;   

DOI  :  10.1590/S0103-50531997000300003

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

The genus Pterodon is widely distributed in the Brazilian savannah, and includes different species among which P. apparicioi Pedersoli and P. polygalaeflorus Benth are commonly know as "Sucupira-Branca"2. Alcoholic infusions from the fruit are employed in Brazilian folk medicine for rheumatic affection and throat infections3. Since it was verified that the furane-diterpene 6a,7b-di-hydroxyvoua capan-17b-oic acid I (ADV), isolated from the hexane extract from the fruit of Pterodon polygalaeflorus Benth, presents anti-inflammatory and analgesic activity3,4, a variety of derivatives of ADV has been synthesized in order to obtain more information about the structure-activity relationship of this series of compounds4,5.    Here we now report the synthesis of seven new amide derivatives of I, according to Scheme 1, and the complete assignment of their 1H- and 13C-NMR data. The main purpose of this paper is the structural characterization of these compounds employing mainly one-and two-dimensional NMR.    Experimental All reactions were followed by analytical thin-layer chromatography (TLC, Merck Sílica Gel 60G, 3:2:1 hexane:dichloromethane:ethanol). Melting points were observed on a Mettler FP 82 HT and are not corrected. Elemental analyses were obtained on a Perkin Elmer 2400 apparatus. Infrared spectra were taken on a Shimadzu IR 408 spectrophotometer on KBr disks. 1H- and 13C-NMR spectra were recorded on a JEOL EX 400 (1H: 400 MHz; 13C: 100 MHz), Bruker AC 200 (1H: 200 MHz; 13C: 50 MHz), or Bruker AC 80 (1H: 80 MHz; 13C: 20 MHz) spectrometer. The NOE difference spectrum was recorded on a Bruker DRX 400 spectrometer. Tetramethylsilane was utilized as the internal standard (d = 0). The 13C signals due to CH/CH3 and CH2 were assigned according to the DEPT 135 13C-NMR spectra. Multiplicities are indicated by s (singlet), d (doublet),dd (double doublet), t (triplet), q (quartet), m (multiplet), and b (broad). Low resolution mass spectra were obtained on a Varian Mat 311 A instrument operating at 70 eV. ADV derivatives were prepared as indicated in Scheme 1, according to the methods described below1.   General experimental procedure (X) mmol of lactone II and (Y) mmol of the respective amine were added to 20.0 mL of THF. The reaction mixture was stirred for (Z) hr under reflux or at room temperature, and monitored by TLC and infrared spectroscopy. After completion of the reaction, the mixture was poured over crushed ice. The resulting white solid was filtered off, washed with water, air dried and recrystallized (see Table 1). In the

【 授权许可】

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