Scheme 3.
Synthesis of diamines 25a and 25b. Reagents: (a) R1P+Ph3Br−, KHMDS, toluene; (b) H2, 10% Pd/C, Boc2O, MeOH; (c) 4 N HCl=Et2O.
Synthesis of diamines 25a and 25b. Reagents: (a) R1P+Ph3Br−, KHMDS, toluene; (b) H2, 10% Pd/C, Boc2O, MeOH; (c) 4 N HCl=Et2O.