Oxazolone spiroisoxazolines

TABLE 7.49. OXAZOLONE SPIROISOXAZOLINES FROM 1,3-DIPOLAR CYCLOADDITION REACTION OF UNSATURATED 5(4H)-OXAZOLONES WITH NITRILE OXIDES... 

The reaction of nitrile oxides with 4-arylmethylene-5(4//)-oxazolones 675 to give the corresponding spiroisoxazoline oxazolones 676 is also well known.The regiochemistry of this cycloaddition reaction was initially incorrectly assigned but a careful study of the reaction showed that the regiochemistry of the 1,3-dipolar cycloaddition of nitrile oxides is the same as that observed with nitrile imines (Scheme 7.213). Examples of spiroisoxazoline oxazolones are shown in Table 7.49 (Fig. 7.60). 

---

See also in sourсe #XX -- [ ]

---