Organocatalytic entry to chiral bicyclo[3.n.1]alkanones via direct asymmetric intramolecular aldolization.
[reaction: see text] The facile stereoselective syntheses of endo-8-hydroxybicyclo[3.3.1]nonan-2-one and endo-7-hydroxybicyclo[3.2.1]octan-2-one, featuring an alpha-amino acid catalyzed intramolecular aldolization of sigma-symmetric substrates, are described. A high enantioselectivity and a high catalytic efficiency have been exhibited by (4R,2S)-tetrabutylammonium 4-TBDPSoxy-prolinate in the aldolization of 3-(4-oxocyclohexyl)propionaldehyde to give highly enantiomerically enriched (1S,5R,8R)-8-hydroxybicyclo[3.3.1]nonan-2-one.
Itagaki
Noriaki
N
Graduate School of Pharmaceutical Sciences, Tohoku University, Aobayama, Sendai 980-8578, Japan.
Kimura
Mari
M
Sugahara
Tsutomu
T
Iwabuchi
Yoshiharu
Y
D000447:Aldehydes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D013237:Stereoisomerism; D013379:Substrate Specificity
D000447:Aldehydes; D000475:Alkenes