Novel approach to the ring-opening of 4-isoxazolines: One-pot synthesis of α,β-enones
摘要:
Treatment of 4-isoxazoline derivatives with methyl iodide affords alpha-beta-enones in excellent yields. The novel rearrangement pathway, proceeding through an intermediate isoxazolinium salt, is interpretable on the basis of the base removal of the hydrogen atom at N-CH3 group.
A simple, fast, efficient and eco-friendly procedure was developed for the synthesis of alkyl and aryl-N-methylnitrones. The corresponding nitrones of aromatic aldehydes, aliphatic aldehydes and alicyclic carbonyl compounds were prepared from N-methylhydroxylamine hydrochloride and Na2CO3-Na2SO4 by simply grinding at room temperature without using solvent.
Thermal Valence Rearrangements of Heterocycles. Part 2. A new synthetic approach towards the indole ring system
作者:Grace A. Bennett、George B. Mullen、Vassil St. Georgiev
DOI:10.1002/hlca.19890720808
日期:1989.12.13
A new syntheticapproach towards the indole ring system is described. When dimethyl 1-methyl-2-oxa-1-aza-spiro[4.5]dec-3-ene-3,4-dicarboxylate (6) was refluxed in toluene, the previously known dimethyl 4,5,6,7-tetra-hydro-1-methyl-1H-indole-2,3-dicarboxylate (7) was obtained in 71% yield, via a 2,3-dihydroisoxazole-pyrrole rearrangement. After treatment with DDQ, the tetrahydro analogue 7 was converted
Tin-free radical alkylation of ketones viaN-silyloxy enamines
作者:Hyun-Ji Song、Che Jo Lim、Sunggi Lee、Sunggak Kim
DOI:10.1039/b606295d
日期:——
The radical alkylation of ketones is achieved by their conversion into corresponding N-silyloxy enamines, followed by a radical reaction with alkyl halides bearing electron-withdrawing groups.
Anionic Diels–Alder Chemistry of Cyclic Sodium Dien-1-olates Delivering Highly Stereoselective and Functionalized Polycyclic Adducts
作者:Jing-Kai Huang、Kak-Shan Shia
DOI:10.1021/acs.orglett.1c01807
日期:2021.8.6
Anionic Diels–Alderchemistry of electron-deficient cross-conjugated vinylogous alkenones, providing highly stable sodium dienolate ion pairs as electron-rich dienes in the presence of a weak sodium base in THF, has been newly developed, leading to a single Diels–Alder adduct, in racemic form, in moderate to high yields (up to 97%, 37 examples).
Synthesis of α-amidoketones. An application of the multi-hetero cope rearrangement
作者:Ivan Lantos、wei-Yuan Zhang
DOI:10.1016/0040-4039(94)88053-0
日期:1994.8
N-methylcarboximidoyl chloride affords after hydrolytic workup α-amidoketones. The results are interpreted in terms of the formation of an intermediate capable of undergoing a facile [3,3] sigmatropic rearrangement. Aldehyde derived nitrones form imides via a [3+2] cycloaddition reaction.