Multi-step reaction with 8 steps
1.1: carbonyldiimidazole / dimethylformamide / 48 h / 40 °C
1.2: 65 percent / DBU / dimethylformamide / 2 h / 65 °C
2.1: 79 percent / DMAP; Et3N / CH2Cl2 / 8 h / 20 °C
3.1: 60 percent / LDA; HMPA / tetrahydrofuran / 18 h / -78 - 20 °C
4.1: 82 percent / TBAF / tetrahydrofuran / 0.33 h / 20 °C
5.1: 33 percent / diethyl azodicarboxylate; Ph3P / CH2Cl2 / 3 h / 20 °C
6.1: 81 percent / triisopropylsilane; trifluoroacetic acid / CH2Cl2 / 0.17 h / 20 °C
7.1: 56 percent / diethyl azodicarboxylate; Ph3P / CH2Cl2 / 4 h / 20 °C
8.1: 59 percent / diethyl azodicarboxylate; Ph3P / CH2Cl2 / 2 h / 20 °C
With
N,N,N,N,N,N-hexamethylphosphoric triamide; dmap; chlorotriisopropylsilane; tetrabutyl ammonium fluoride; triethylamine; triphenylphosphine; 1,1'-carbonyldiimidazole; trifluoroacetic acid; lithium diisopropyl amide; diethylazodicarboxylate;
In
tetrahydrofuran; dichloromethane; N,N-dimethyl-formamide;
5.1: Mitsunobu alkylation / 7.1: Mitsunobu alkylation / 8.1: Mitsunobu alkylation;
DOI:10.1039/b302239k