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.
Keywords: (5α)-Cholestane; Aluminacyclopentane; Cycloalumination; Dzhemilev reaction; Spiranes; Zirconocene dichloride.
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