References
- Schmidt , U. , Lieberknecht , A. and Wild , J. 1988 . Synthesis , : 159
- Wulff , G. and Bohnke , H. 1986 . Angew. Chem. Int. Ed. Engl. , 25 : 90 G. Wulff, H. Bohnke and H. T. Klinken, Ann., 501 (1988)
- Tarzia , G. , Balsamini , C. , Spadoni , G. and Duranti , E. 1988 . Synthesis , : 514
- Bayard , Ph. , Sainte , F. , Beaudegnies , R. and Ghosez , L. 1988 . Tetrahedron Lett. , : 3799 and references cited therein
- Balsamini , C. , Duranti , E. , Mariani , L. , Salvatori , A. and Spadoni , G. 1990 . Synthesis , : 779 For the synthesis of (Z)- and (E)-1c,d, see
- In preliminary cycloaddition experiments (toluene, reflux, 8 hrs), 1a and dimethyl acetylenedicarboxylate reacted to give the expected trimethyl 2,2-diphenyl-1,2-dihydropyridine-3,4,6-tricarboxylate in about 50% yield, mp. 214–215° (toluene). This structure was confirmed by spectroscopic (IR, NMR) and microanalysis data