2-Oxazolidone ring opening

In a scheme intended to produce a more highly substituted oxazolidone, epichlorohydrin is condensed with morpholine in the presence of strong base to give the aminoepoxide, 27. Ring opening of the oxirane by means of hydrazine gives the hydroxy-hydrazine (28). Ring closure with diethyl carbonate leads to the substituted oxazolidone (29). Condensation with 18 affords furaltadone (30). ... 

Thermolysis of lactones yielded reactive species either by loss of carbon dioxide or, in the case of the oxazolidone 324, by ring opening to the azomethine ylide 325. If the thermolysis of oxazolidone 324 is carried out in the presence of R1RZC=X, a formal 1,3-dipolar cycloaddition occurs to give racemic oxapenams 326 (Scheme 10) in poor to moderate yield <1999CC249, 2001J(P 1)1281 >. 

Ho et al (1996) examined polyol or polysiloxane thermoplastic polyurethanes (TPUs) as modifiers in cresol-formaldehye novolac epoxy resins cured with phenolic novolac resin for computer-chip encapsulation. A stable sea-island dispersion of TPU particles was achieved by the epoxy ring-opening with isocyanate groups of the urethane prepolymer to form an oxazolidone. The flexural modulus was reduced by addition of TPU and also the Tg was increased due to the rigid oxazolidone structure. Mayadunne et al (1999) extended this work to a series of phenol- and naphthol-based aralkyl epoxy resins. 

Another "oxazolidone driven" synthesis reacted 6.162 with benzyl isocyanate to give 6.163. Reduction of the aldehyde to an alcohol and adjustment of pH led to formation of 6.164, but with poor diastercoselectivity (isolated as a 1 1 cis trans mixture). Incorporation of the isobutenyl group and ring opening gave 6.165. Hydro-... 

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