摘要
Syntheses of (1R,2S,3R,4S)-1,7,7-trimethyl-2-pyridin-2-ylmethylbicyclo[2.2.1]-heptane-2,3-diol (7), (1R,2S,3R,4S)-1,7,7-trimethyl-2-[(6-methyl)-pyridin-2-ylmethyl-bicyclo-[2.2.1]heptane-2,3-diol (13), and (1R,2S,2’R,4R)-1,7,7-trimethyl-2-piperidin-2-ylmethyl-bicyclo[2.2.1]heptan-2-ol (19b) from commercially available (d)-camphor (1) are described. Key steps of the syntheses involved substrate-controlled diastereoselective alkylation and platinum oxide-catalyzed hydrogenation reactions. These compounds, and other intermediate amino alcohols in their syntheses, were successfully utilized as ligands in enantioselective diethyl zinc (Et2Zn) addition to benzaldehyde with moderate enantioselectivity.
Syntheses of (1R,2S,3R,4S)-1,7,7-trimethyl-2-pyridin-2-ylmethylbicyclo[2.2.1]-heptane-2,3-diol (7), (1R,2S,3R,4S)-1,7,7-trimethyl-2-[(6-methyl)-pyridin-2-ylmethyl-bicyclo-[2.2.1]heptane-2,3-diol (13), and (1R,2S,2’R,4R)-1,7,7-trimethyl-2-piperidin-2-ylmethyl-bicyclo[2.2.1]heptan-2-ol (19b) from commercially available (d)-camphor (1) are described. Key steps of the syntheses involved substrate-controlled diastereoselective alkylation and platinum oxide-catalyzed hydrogenation reactions. These compounds, and other intermediate amino alcohols in their syntheses, were successfully utilized as ligands in enantioselective diethyl zinc (Et2Zn) addition to benzaldehyde with moderate enantioselectivity.
