[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.
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