54848-13-4Relevant academic research and scientific papers
Efficient Synthesis of O - Tert -Propargylic Oximes via Nicholas Reaction
Nakamura, Itaru,Shiga, Keigo,Suzuki, Mao,Terada, Masahiro
, p. 3461 - 3465 (2020/08/10)
A synthetic protocol to access O - tert -propargylic oximes derived from tertiary propargylic alcohols was established via Nicholas reaction. Thus, BF 3·OEt 2-mediated reaction between the dicobalt hexacarbonyl complex of tert -propargylic alcohols and p -nitrobenzaldoxime followed by decomplexation with cerium(IV) ammonium nitrate afforded the corresponding O - tert -propargylic oximes in good to high yields. The obtained O - tert -propargylic oximes were effectively converted into heterocycles, such as four-membered cyclic nitrones, oxazepines, and isoxazolines, by using π-Lewis acidic catalysts.
Rearrangement of isoxazoline-5-spiro derivatives. Part 7. Thermal rearrangement of 4,5-dihydro and tetrahydroisoxazole-5-spirocyclobutanes to azepin-4-one derivatives
Goti,Brandi,De Sarlo,Guarna
, p. 5283 - 5300 (2007/10/02)
Some representative 4,5-dihydro and tetrahydroisoxazole-5-spirocyclobutanes have been synthesized by 1,3-dipolar cycloaddition of alkylidenecyclobutanes to nitrile oxides and nitrones, respectively. When subjected to flash vacuum thermolysis conditions, the spiranic cycloadducts rearranged to afford mainly the desired azepin-4-one derivatives. In addition, the isoxazoline cycloadducts gave unexpected by-products, which were identified as 1-alkenyl-2-pyrrolidinones. Analogies and differences with respect to the lower homologue cyclopropanes are evidenced in both cycloaddition and rearrangement reactions.
