Multi-step reaction with 14 steps
1: 1) butyllithium / 1) ether, hexane, -42 to 0 deg C, 2) ether, hexane, -42 deg C, 10 min.
2: CrO3*2pyridine / CH2Cl2 / 0.5 h / Ambient temperature
3: aluminum amalgam / tetrahydrofuran / Ambient temperature
4: sodium borohydride / ethanol / 1 h / 0 °C / further reag.: LiAlH4, Zn(BH4), DIBAL, B2H6
5: pyridinium p-toluolsulfonate / CH2Cl2 / Ambient temperature
6: hydrogen / palladium hydroxide on carbom / ethyl acetate / 6 h
7: 1) DMSO, oxalyl chloride, 2) triethylamine / 1) CH2Cl2, - 78 deg C 2) CH2Cl2, -78 to 0 deg C
8: 1)n-butyllithium / 1) THF, RT, 30 min, 2) THF, -78 deg C then reflux, 2 h
9: trimethylbromosilane / CH2Cl2 / 1) -78 deg C, 15 min, 2) -25 deg C, 30 min.
10: 60percent sodium hydride / tetrahydrofuran; dimethylformamide / 16 h / Ambient temperature
11: n-Bu4NF / tetrahydrofuran; acetonitrile / Ambient temperature
12: 1) DMSO, oxalyl chloride, 2) triethylamine / 1) CH2Cl2, -78 deg C, 15 min, 2) CH2Cl2, -78 to 0 deg C
13: 1) sec-BuLi / 1) THF, hexane, -78 deg C, 10 min, 2) THF,hexane, -78 deg C, 20 min.
14: pyridine / 55 °C
With
pyridine; sodium tetrahydroborate; n-butyllithium; oxalyl dichloride; trimethylsilyl bromide; aluminium amalgam; tetrabutyl ammonium fluoride; hydrogen; sec.-butyllithium; pyridinium p-toluenesulfonate; dipyridine chromium trioxide; sodium hydride; dimethyl sulfoxide; triethylamine;
palladium hydroxide - carbon;
In
tetrahydrofuran; ethanol; dichloromethane; ethyl acetate; N,N-dimethyl-formamide; acetonitrile;
DOI:10.1016/S0040-4020(01)86918-0