e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Synthesis of 2, 2-disubstituted 7-methylenenorbornanes with 2-exo functionality by Diels-Alder reaction of 5, 5-dimethoxytetrachlorocyclopentadiene
HW Thompson, JK Wong, RA Lalancette…
Index: Thompson, Hugh W.; Wong, Jesse K.; Lalancette, Roger A.; Boyko, Jean A.; Robertiello, Anthony M. Journal of Organic Chemistry, 1985 , vol. 50, # 12 p. 2115 - 2121
Diels-Alder reaction of 5, 5-dimethoxytetrachlorocyclopentadiene (2) with methyl methacrylate gave only the endo-carbomethoxybicycloheptene adduct 4N, confirmed by single-crystal X-ray analysis. Methylation of the endo adduct 3 of methyl acrylate and 2 gave only 4N. Saponification and dehalogenation of 3 gave carboxy ketal 7, whose methyl ester 9 also gave only endo-carbomethoxy product 10 upon alkylation. Reaction of 2 with ...