1,8-diazabicyclo[5.4.0]undec-7-ene; lithium chloride in acetonitrile 4 h;

1: SOCl2, MgSO4 / 10 h / 50 °C 2: 75 percent / 2N aq. NaOH / 25 °C / pig liver esterase 3: Et3N / tetrahydrofuran / 0.25 h / -15 °C 4: NaBH4, MeOH / tetrahydrofuran / 2 h / 0 °C 5: 1.) (COCl)2, DMSO, 2.) Et3N / 1.) CH2Cl2, -60 deg C 6: 1.) LiCl, DBU / 1.) MeCN, RT, 1 h, 2.) MeCN, RT, 4 h View Scheme

1: 1.) BuLi 2: SOCl2, MgSO4 / 10 h / 50 °C 3: 75 percent / 2N aq. NaOH / 25 °C / pig liver esterase 4: Et3N / tetrahydrofuran / 0.25 h / -15 °C 5: NaBH4, MeOH / tetrahydrofuran / 2 h / 0 °C 6: 1.) (COCl)2, DMSO, 2.) Et3N / 1.) CH2Cl2, -60 deg C 7: 1.) LiCl, DBU / 1.) MeCN, RT, 1 h, 2.) MeCN, RT, 4 h View Scheme

1: 75 percent / 2N aq. NaOH / 25 °C / pig liver esterase 2: Et3N / tetrahydrofuran / 0.25 h / -15 °C 3: NaBH4, MeOH / tetrahydrofuran / 2 h / 0 °C 4: 1.) (COCl)2, DMSO, 2.) Et3N / 1.) CH2Cl2, -60 deg C 5: 1.) LiCl, DBU / 1.) MeCN, RT, 1 h, 2.) MeCN, RT, 4 h View Scheme