SN1-like Reactions of Bicyclic α-Amino Ethers with Sulfur, Nitrogen, and Carbon Nucleophiles. Synthesis of 1-Azabicyclo[3.2.2]nonanes Functionalized at Carbon C2 and C6 with Complete Stereocontrol
journal contributionposted on 2002-09-12, 00:00 authored by Stefanie Röper, Rudolf Wartchow, H. Martin R. Hoffmann
In the presence of nucleophiles, Lewis acid mediated cleavage of α-amino ethers derived from quincorine and quincoridine affords a variety of C2-substituted and C6-vinylated 1-azabicyclo[3.2.2]nonanes. These are enantiopure and are formed in SN1-like reactions with complete stereocontrol. There is no leakage into 2-Nu en route to product 1-Nu or vice versa. Me3SiCN provides new Strecker-type α-amino nitriles. In the presence of TTMPP−BF3·OEt2, the ketene acetal Me2CC(OMe)OSiMe3 delivers enantiopure bicyclic β-amino acid esters.