Amino acid mediated intramolecular asymmetric aldol reaction to construct a new chiral bicyclic enedione containing a seven-membered ring: remarkable inversion of enantioselectivity compared to the six-membered ring example.
A detailed study to assess the enantioselectivity of the amino acid mediated intramolecular asymmetric aldol reaction of 1,3-cycloheptanedione bearing a C-2 methyl substituent has been undertaken. The cyclizations were mediated by a series of l-amino acids in the presence of an acid cocatalyst. Strikingly, the process is characterized by an inversion of enantioselectivity when compared to a similar reaction involving the 1,3-cyclohexanedione counterpart.
Nagamine
Takashi
T
Tohoku Pharmaceutical University, 4-4-1 Komatsushima Aoba-ku, Sendai 981-8558 Japan.
Inomata
Kohei
K
Endo
Yasuyuki
Y
Paquette
Leo A
LA
D000596:Amino Acids / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D012997:Solvents; D013237:Stereoisomerism
D000596:Amino Acids; D001643:Bridged Bicyclo Compounds; D012997:Solvents