Spectroscopic Analysis of IK

El mass spectra of IK-1 gave stronger molecular ion peaks. Fragment ions of IK-1 were consistent with the stmcture and could be assigned. 

However, protons (OCHP) in compounds with Et and n-Pr as R appeared as multiplets which were split by the effect of the magnetic nucleus firom both phosphorus and proton in R, such as IK-5 and IK-6. The chemical shifts of proton signal in the OCHP could be affected by the structure of R. For compounds with Et as R, its signal in the OCHP appeared at 8 5.1-5.4 ppm, while for compounds with Ph or substituted Ph as R, proton signals in the OCHP appear at 62-6.6 ppm. This 

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