Catalytic cycloalumination in steroid chemistry II: selective functionalization of 2'-methylidene-2',3'-ethano-(5α)-cholestane.
The catalytic cycloalumination of 2'-methylidene-2',3'-ethano-(5α)-cholestane with Et3Al catalyzed by Cp2ZrCl2 was performed for the first time to give spiro[2',3'-ethano-(5α)-cholestane-2',3″-aluminacyclopentane] in a ~75% yield and with high stereoselectivity (>98%). The obtained cyclic organoaluminum compound was transformed in situ into heterocyclic spiran derivatives of 2',3'-ethano-(5α)-cholestane.
Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, pr. Oktyabrya 141, 450075 Ufa, Russian Federation. Electronic address: DyakonovVA@rambler.ru.
Vladimir A
VA
D'yakonov
Regina A
RA
Tuktarova
Ilgiz I
II
Islamov
Leonard M
LM
Khalilov
Usein M
UM
Dzhemilev
D002384:Catalysis; D002776:Cholestanes / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis*; D061565:Cycloaddition Reaction; D009942:Organometallic Compounds / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis*; D015040:Zirconium / Q000737:chemistry*
D002776:Cholestanes; D056831:Coordination Complexes; D009942:Organometallic Compounds; D013141:Spiro Compounds; C023398:Zirconocene dichloride; D015040:Zirconium; C498384:triethylaluminum
(5α)-Cholestane; Aluminacyclopentane; Cycloalumination; Dzhemilev reaction; Spiranes; Zirconocene dichloride