Blanc cyclization / reaction

The hydrolysis of aphylline and of aphyllidine (XCV) gives aphyllinic acid (mp 214°) and aphyllidinic acid (mp 221°), respectively. Aphyllinic acid can be converted into sparteine by the following sequence of reactions esterification, Bouveault-Blanc reduction, chlorination, and cyclization with alkali 76). Aphylline and aphyllidine react with sodium amide in benzene solution to give the corresponding amides, XCVI and XCVII (77). 

Blanc reaction-Blanc rule. Cyclization of dicarboxylic acids on heating with acetic anhydride to give either cyclic anhydrides or ketones, depending on the positions of the carboxyl groups 1,4- and 1,5-diacids give anhydrides, while diacids in which the carboxy groups are in 1,6- or further-removed positions give ketones. 

Azetidine synthesis Paterno-Buchi reaction Photochemical cyclizations Blanc reaction (n = )... 

Kern, N., Blanc, A., Miaskiewicz, S., Robinette, M., Weibel, J.-M., Pale, P. (2012). Coinage metals-catalyzed cascade reactions of aryl alkynylaziridines silver(I)-single vs gold(I)-double cyclizations, Journal of Organic Chemistry, 77, 4323 -4341. 

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