405506-88-9Relevant articles and documents
Enantioselective, Lewis Base-Catalyzed Sulfenocyclization of Polyenes
Tao, Zhonglin,Robb, Kevin A.,Zhao, Kuo,Denmark, Scott E.
supporting information, p. 3569 - 3573 (2018/03/21)
A sulfenium-ion-initiated, catalytic, enantioselective polyene cyclization is described. Homogeranylarenes and ortho-geranylphenols undergo polycyclization in good yield, diastereoselectivity, and enantioselectivity. The stereodetermining step is the generation of an enantiomerically enriched thiiranium ion from a terminal alkene and a sulfenylating agent in the presence of a chiral Lewis basic catalyst. The use of hexafluoroisopropyl alcohol as the solvent is crucial to obtain good yields. The thioether moiety resulting from the reaction can be subsequently transformed into diverse oxygen and carbon functionality postcyclization. The utility of this method is demonstrated by the enantioselective syntheses of (+)-ferruginol and (+)-hinokiol.
Regioselective palladium-catalyzed alkylation of allylic halides with benzylic Grignard reagents. Two-step synthesis of abietane terpenes and tetracyclic polyprenoid compounds
Rosales, Viale,Zambrano, Jorge L.,Demuth, Martin
, p. 1167 - 1170 (2007/10/03)
A highly regioselective palladium-catalyzed α-alkylation of allylic bromides 1a,c-e and chloride 1b with substituted and unsubstituted benzylic Grignard reagents is reported. The resulting alltrans polyenehomobenzene derivatives were obtained in excellent yields and regioselectivity. These products were easily converted to abietane-type diterpenes (10-12) and tetracyclic polyprenoid compounds (13, 14) through a Lewis acid-promoted cascade polyene cyclization reaction.
