- Asymmetric synthesis of highly substituted β-lactones by nucleophile-catalyzed [2+2] cycloadditions of disubstituted ketenes with aldehydes
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α,α-Disubstituted β-lactones can be obtained by the cycloaddition of the corresponding ketenes with aldehydes (see scheme). For the first time, a chiral PPY derivative, 1, serves as an efficient catalyst for the asymmetric synthesis of β-lactones (PPY = 4-pyrrolidin-1-ylpyridine). To date, this is the only catalyst that is effective for enantioselective cycloadditions of disubstituted ketenes with aldehydes. (Chemical equation presented).
- Wilson, Jonathan E.,Fu, Gregory C.
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p. 6358 - 6360
(2007/10/03)
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