Studies on intramolecular Diels-Alder reactions of furo[3,4-c]pyridines in the synthesis of conformationally restricted analogues of nicotine and anabasine.
En route to conformationally restricted analogues of nicotine and anabasine, a novel synthetic route to bridged anabasines is described that hinges on a domino intramolecular [4 + 2]-cycloaddition/ring opening-elimination sequence of 3-amino-substituted furo[3,4-c]pyridines. Extension of this route to bridged nicotines, however, proved abortive, even when the dienophile tether is activated by a p-tolylsulfonyl group or when the diene moiety is activated by an electron-releasing methoxy substituent. A detailed density functional theoretical study (B3LYP/6-31+G) was undertaken to provide insight into the factors that facilitate an intramolecular Diels-Alder reaction in the former case.
Sarkar
Tarun K
TK
Department of Chemistry, Indian Institute of Technology, Kharagpur-721302, India. tksr@chem.iitkgp.ernet.in
Basak
Sankar
S
Slanina
Zdenek
Z
Chow
Tahsin J
TJ
D000691:Anabasine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D007202:Indicators and Reagents; D008962:Models, Theoretical; D008968:Molecular Conformation; D015394:Molecular Structure; D009538:Nicotine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry
D007202:Indicators and Reagents; D011725:Pyridines; D009538:Nicotine; D000691:Anabasine