J. D'angelo, F. Dumas, M. Pizzonero
Dec 31, 2005
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Influential Citations
7
Citations
Journal
Heterocycles
Abstract
An enantioselective synthesis of (R)-l-azaspiro[4.4]nonane-2,6-dione ethylene ketal (4), chiral relay in the elaboration of (-)-cephalotaxine (1b), starting from (R)-1-(2-methoxycarbonylethyl)-2-oxo-cyclopentanecarboxylicacid methyl ester ((R)-10) (8 chemical operations, 26% overall yield, ee ≥ 95%) is described. The Curtius rearrangement of acyl azide (12) was used as the key strategic element to install with a perfect stereochemical fidelity and a high efficiency an α-nitrogen substituent at the quaternary carbon center in 10.