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DOI: 10.1055/s-0029-1219954
Efficient and Atom-Economic Synthesis of α-Substituted β-Chromonyl-α,β-unsaturated Carbonyls through Molecular Rearrangement
Publikationsverlauf
Publikationsdatum:
04. Juni 2010 (online)
A wrong NMR prediction between the ester carbonyls
of the keto ester and conjugated ester moieties in 4f led
us to a wrong stereochemical assignment (coincidentally rightly
captioned, however). Keto esters 4a-
g
should be read
in E-configuration in Table 1 and Schemes
2-4. The corrected Figure 1 (structure B)
and the corresponding modified paragraph (on page 404 of the original
manuscript) are given below. The authors apologize for these mistakes.
Similar
NOE effects were observed in the case of keto ester 4f.
While irradiation of C2-H in 4f resulted
in signal enhancement of C1′-H, the latter on irradiation
led to the signal enhancement for C2-H besides a weak signal enhancement for
the methylene(-OCH
2Me) proton
of conjugated ester (established by HMBC
and HSQC NMR experiments) (Figure 1, B).
Thus, E-configuration was assigned to
the keto esters 4a-g.
![](https://www.thieme-connect.de/media/synlett/201010/r11010st.gif)
Figure 1