27930-43-4Relevant academic research and scientific papers
Haloacetylated Enol Ethers. 5. Heterocyclic Ring Closure Reactions of β-Alkoxyvinyl Dichloromethyl Ketones with Hydroxylamine
Martins, Marcos A. P.,Zoch, Alana N.,Flores, Alex F. C.,Clar, Guenter,Zanatta, Nilo,Bonacorso, Helio G.
, p. 739 - 742 (2007/10/02)
The β-alkoxyvinyl dichloromethyl ketone 1a-d are cyclocondensed with hydroxylamine hydrochloride in pyridine to afford the 5-hydroxy-5-dichloromethyl-4,5-dihydroisoxazoles 2a-d in good yield.The cyclocondensation of compound 1c gave, together with 2c, 3-cyano-2-hydroxy-2-dichloromethyltetrahydrofuran 5c.The dehydratation of compounds 2a,b, derived from acyclic enol ethers, with concentrated sulfurc acid at 30 deg C, led the corresponding 5-dichloromethylisoxazoles 3a,b.The dehydratation of compounds 2c,d, derived from cyclic enol ethers, with concentrated sulfuric acid at 30 deg C, led the bicyclic 4,5-dihydroisoxazoles 4c,d, and at 55 deg C, a competitive rearrangement reaction gives the 3-cyano-2-hydroxy-2-dichloromethyl-2H-pyran 5d.
