Use of chiral-pool approach into epi-thieno analogues of the scarce bioactive phenanthroquinolizidine alkaloids

TETRAHEDRON

卷:72

Article

Safar, Peter¹  Marchalin, Stefan¹  Pronayova, Nadezda²  Vrabel, Viktor³  Lawson, Ata Martin⁴  Othman, Mohamed⁴  Daich, Adam⁴ 

[1] Slovak Univ Technol Bratislava, Fac Chem & Food Technol, Dept Organ Chem, SK-81237 Bratislava, Slovakia

[2] Slovak Univ Technol Bratislava, Fac Chem & Food Technol, Cent Labs, SK-81237 Bratislava, Slovakia

[3] Slovak Univ Technol Bratislava, Fac Chem & Food Technol, Dept Analyt Chem, SK-81237 Bratislava, Slovakia

[4] Normandie Univ, UNILEHAVRE, CNRS, URCOM, F-76600 Le Havre, France

关键词: 6-Oxopipecolinic acid;    pi-Cationic cyclization;    Diastereoselective reduction;    Thienoquinolizidine;    Phenanthroquinolizidine alkaloids;   

DOI  :  10.1016/j.tet.2016.04.047

来源: Elsevier

【 摘 要 】

The stereoselective synthesis of epi-thieno analogues of the phenanthroquinolizidine bioactive alkaloids (-)-Cryptopleurine and (-)-(15R)-Hydroxycryptopleurine was achieved in five steps starting from easily available enantiopure (S)-2-aminoadipic acid used as chiral pool and nitrogen atom source. During these investigations, both pi-cationic cyclization of chiral N-thienylmethyl-6-oxopipecolinic acids into pure (S)-keto-lactams and theirs regioselective and diastereoselective reduction, considered as key steps of this sequence, were studied. Of particular interest, the Friedel-Crafts cyclization using (CF3CO)(2)O/BF3 center dot Et2O show that near the expected keto-lactams, enamides and enamidones containing trifluoromethyl residue were isolated. A mechanism leading to the latter products with high synthetic potential was discussed. (c) 2016 Published by Elsevier Ltd.

【 授权许可】

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