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Journal articles
New advances in stereoselective Meyers’ lactamization. Application to the diastereoselective synthesis of β-substituted oxazoloazepinones
Abstract : A stereoselective approach to the preparation of 7,5-fused bicyclic lactams based on Meyers’ lactamization is presented. The lactamization step is conducted at 0 °C with 6-oxohexanoic acid 1 and with various chiral aminoalcohols in the presence of 2-fluoro-1-ethylpyridinium tetrafluoroborate (FEP) as an activating agent. Under these mild conditions, bicyclic lactams 2–4 were obtained in satisfactory yields and diastereoselectivities up to 95%. To account for the high level of diastereoselection, the mechanistic aspects of Meyers’ lactamization were investigated by means of in situ infrared spectroscopy. Finally, the lactam enolate derived from 2 was subjected to reaction with various electrophiles, furnishing the corresponding β-substituted oxazoloazepinones 5–9 in good yields (up to 86%) and in moderate to excellent diastereoselectivities ranging from 27% to 95% de.
https://hal-normandie-univ.archives-ouvertes.fr/hal-02278757
Contributor : Sylvain Oudeyer Connect in order to contact the contributor
Submitted on : Wednesday, September 4, 2019 - 3:45:10 PM
Last modification on : Tuesday, October 19, 2021 - 11:34:48 PM
Contributor : Sylvain Oudeyer Connect in order to contact the contributor
Submitted on : Wednesday, September 4, 2019 - 3:45:10 PM
Last modification on : Tuesday, October 19, 2021 - 11:34:48 PM
