New Synthesis Of N-Oxazolidine-2,4-Diones And 1,6-Methano[10]Annulene-3,4-Carbolactone's Synthesis With Characterization

This article is composed of two parts.Part one is the new synthesis of oxazolidine-2,4-diones,involving study on their characters.Part two is about the synthesis and characterization of a new kind ofγ-lactone called 1,6-methano[10]annulene-3,4-carbolactone.The first part of this study is about the synthesis and characterization of oxazolidine-2,4-diones.The key intermediate salt 2 was obtained by cycloaddition reaction of urea,sodium methoxide(or potassium isopropoxide)and diester 1 which was prepared from methyl-chloroacetate and potassium acetate. Then oxazolidine-2,4-dione 3(yield 90.1%)was obtained by acidifying salt 2, and oxazolidine-2,4-dione derivatives 4a-c(corresponding yield 83.1%, 85.4%,89.6%)were synthesized by salt 2 and corresponding halids.The structures of 3 and 4a-c were confirmed by IR,MS,and ¹H NMR spectra.Additionally,this article develop a new synthesis ofγ-lactone4 3,4-Dihydroxymethylene-1,6-methano[10]annulene 13(yield 73.9%)was prepared by reducing compound 12,which was generated from 3,4-Diformaldehyde-1,6-methano[10]annulene 9 in 3 steps(two Wittigreactions and one cyclization-reaction).After oxidating 13,using BaMnO₄,we got 1,6-methano[10]annulene-3,4-carbolactone 14(yield 93.0%).The structures of 13 and 14 were confirmed by IR,MS,¹H NMR and ¹³C NMR spectra,and the mechanism of oxidaction of diol 13 was proposed.