Abstract
4′-Nitro-2H -spiro[acenaphthylene-1,2′-pyrrolidine]-2-one derivatives are prepared via [3+2] cycloaddition
reactions of azomethine ylides, generated in situ from acenaphthoquinone and primary amines, with β-nitrostyrenes in the presence of
(
i
Pr)2 NEt in methanol. Evidence for the structures of the products was obtained from single-crystal
X-ray analysis. The important feature of this diastereoselective synthesis of NH-unprotected
spiropyrrolidines is the formation of four contiguous stereogenic centers, one of
which is quaternary, with high selectivity.
Key words azomethine ylide - Huisgen reaction - spiro compound - β-nitrostyrenes - acenaphthoquinone
