Daphnodorin B synthesis

Yield:-

Steps:

Multi-step reaction with 15 steps
1.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 1 h / 0 °C / Inert atmosphere
2.1: potassium carbonate / acetone / 10 h / 80 °C
3.1: hydrogenchloride; water / methanol / 12 h / 30 °C
4.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.17 h / 0 °C
4.2: Claisen-Schmidt Condensation / 12.67 h / 2 - 20 °C
5.1: triethylamine; chloroformic acid ethyl ester / tetrahydrofuran / 0.55 h / 0 °C
5.2: 0.33 h / 20 °C
5.3: 0.75 h / -10 °C
6.1: 1H-imidazole / N,N-dimethyl-formamide / 0 - 20 °C
7.1: hydroquinidein 1,4-phthalazinediyl diether; methanesulfonamide / tert-butyl alcohol; water / 0 °C
8.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 1.5 h / 20 °C
9.1: pyridinium p-toluenesulfonate; orthoformic acid triethyl ester / 1,2-dichloro-ethane / 5.33 h / 20 - 50 °C
9.2: 20 °C
10.1: N-iodo-succinimide / N,N-dimethyl-formamide / 0 °C
11.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 2 h / 0 - 20 °C
12.1: hydrogenchloride; water / methanol / 3 h / 50 °C
13.1: potassium phosphate / acetonitrile / 75 °C
14.1: palladium diacetate; triphenylphosphine; silver carbonate / acetonitrile / 15 h / 115 °C / Inert atmosphere
15.1: boron tribromide / dichloromethane / 10 h / -78 - 40 °C / Inert atmosphere

References:

Yuan, Hu;Bi, Kai-Jian;Li, Bo;Yue, Rong-Cai;Ye, Ji;Shen, Yun-Heng;Shan, Lei;Jin, Hui-Zi;Sun, Qing-Yan;Zhang, Wei-Dong [Organic Letters,2013,vol. 15,# 18,p. 4742 - 4745]