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In our first report concerning the reactions of 1,2-and 1,3-dicarbonyl compounds with dimethyl /3-ketoglutarate (1), we proposed structure 3a for the product obtained from reaction of cyclohexane-1,3-dione (2a) with 1 at pH 6.8. This structure has now been revised to methyl 5,6,7,8-tetrahydro-5-oxocoumarin-4-yl acetate (4a) based on UV and 13C NMR data. In addition, the tetrahydro-5-oxocoumarin derivatives 4a and 4b were converted to the corresponding 5,6,7,8-tetrahydro-5-oxo-2-quinolones 10a, 11a, 10b, and lib, respectively, by reaction with N-benzylamine or ammonia. The 13C NMR spectra of these 2-quinolones are presented and discussed.During studies on the reaction of dicarbonyl com-poundsli2a"c with dimethyl /3-ketoglutarate (1) we reported, in preliminary form,3 that stirring cyclohexane-1,3-dione (2a) with 1 at pH 6.8 provided the lactone 3a. We would now like to revise the structure of this reaction product to the a-pyrone derivative, methyl 5,6,7,8-tetrahydro-5-oxocoumarin-4-yl acetate (4a),4 based on analogies between the UV and 13C NMR spectra of 4a with the spectra of 4-methyl-5,6,7,8-tet-

Scheme IIIa a, Na/K, THF, C02 (58%); b, (COCl)2, CH2N2, copper bronze, benzene, 80 0C (43% overall); c, LiCHBr2, BuLi13 (53% overall); d, TsNHNH2, CH3OH (62%); e, LiNO'-Pr),, THF, room temperature (60%).possibility that 4 might also equilibrate with 3, but this now appears to be a remote prospect. Supplementary Material Available. Characterization of compounds 6 and 11, together with the experimental details for preparation of these intermediates (4 pages). Ordering information is given on any current masthead page.