1: CF3COOH / CH2Cl2 2: 1.) H2, 2.) NEt3, EEDQ / 1.) 10percent Pd/C / 1.) MeOH, AcOH, 2.) CH2Cl2 3: 83 percent / tetrabutylammonium fluoride / tetrahydrofuran 4: 1.) N-hydroxysuccinimide, dicyclohexylcarbodiimide / 1.) THF, 0 deg C, 30 min, 2.) CHCl3, 4h 5: 30percent HBr-HOAc / CH2Cl2 / 0.22 h 6: CH2Cl2 / 18 h 7: 0.085 g / Zn / tetrahydrofuran / 3 h 8: KHCO3 / methanol / 48 h 9: 98 percent / H2 / 10percent Pd/C / methanol; H2O / 2.5 h View Scheme

Multi-step reaction with 4 steps 1: 81 percent / Zn, AcOH / 3 h / Irradiation2: 100 percent / trifluoroacetic acid / 0.5 h / Ambient temperature3: tetrahydrofuran / 22 h / Ambient temperature4: 87 percent / H2 / 10percent Pd/C / methanol; H2O / 4 h