Syntheses of α,β-Unsaturated Carbonyl Compounds from the Reactions of Monosubstituted Ozonides with Stable Phosphonium Ylides
作者:Yung-Son Hon、Ling Lu、Rong-Chi Chang、Sheng-Wun Lin、Pei-Pei Sun、Chia-Fu Lee
DOI:10.1016/s0040-4020(00)00903-0
日期:2000.11
Ozonides derived from terminal alkenes reacted with 1.3 mol equiv. of stable phosphonium ylides to give (E)-α,β-unsaturated carbonyl compounds in good to excellent yields. No reducing agent is needed in the reaction. However, alkoxyalkyl-substituted ozonides afforded a mixture of (Z)- and (E)-α,β-unsaturated carbonyl compounds under similar condition. The E/Z isomeric ratio is affected by the position
The structures of 1,2,4-trioxolanes (ozonides) (2a-2f) derived from mono-substituted alkenes (1a-1f), respectively, were determined by spectroscopic methods, such as H-1-nmr, C-13-nmr, ir, two-dimensional nmr, and mass spectra. The coupling constant of the geminal protons on the trioxolane ring is zero. This unusual coupling constant resulted from the electronegativity of two oxygen atoms near the geminal protons.
HON, YUNG-SON;LU, LING;LI, SHYH-YUAN, J. CHEM. SOC. CHEM. COMMUN.,(1990) N2, C. 1627-1628