Chemistry of 5-oxodihydroisoxazoles. Part 18.1 Synthesis of oxazoles by the photolysis and pyrolysis of 2-acyl-5-oxo-2,5-dihydroisoxazoles
作者:Rolf H. Prager、Jason A. Smith、Ben Weber、Craig M. Williams
DOI:10.1039/a700134g
日期:——
N-Acylisoxazol-5-ones lose carbon dioxide under
photochemical and thermal conditions affording iminocarbenes which
undergo intramolecular cyclisation through the oxygen of the acyl group
to give oxazoles. Under photochemical conditions those acylisoxazolones
with electron withdrawing groups at C-4 usually give high yields of
oxazoles, while those with electron donating groups at C-4 give only
poor yields: the reverse is observed under thermal conditions.
N-酰基
异恶唑-5-酮在光
化学和热条件下失去
二氧化碳,生成
亚胺卡宾,随后通过酰基团的氧进行分子内环化,形成
恶唑。在光
化学条件下,C-4位带有吸电子基团的酰基
异恶唑酮通常产生高产率的
恶唑,而在C-4位带有供电子基团的酰基
异恶唑酮仅产生低产率:在热条件下观察到相反的结果。