A straightforward route to the asymmetric synthesis of 3,4-diepipolyoxamic acid and its isomers

The shortest route at present for the asymmetric synthesis of 3,4-diepipolyoxamic acid 2 and the isomer of polyoxamic acid 5 has been developed via the diastereoselective aldol reaction of camphor-based tricyclic iminolactones 3 and 4 with good stereoselectivities (dr: 12:1 and 9:1) and high yields.