Stereocontrolled Lactonization Reactions via Palladium-Catalyzed 1,4-Addittion to Conjugated Dienes
1993 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 58, no 20, 5445-5451 p.Article in journal (Refereed) Published
Stereocontrolledp alladium(I1)-catalyzed1 ,4-chloro-and 1,4-acetoxylactonizations o f conjugated cyclic dienes have been developed to give stereodefined fused lactones. The stereochemistry of the 1,4- acetoxylactonization was controlled by the ligand on the metal catalyst, and in this way either a cisor truns-acetoxylactonization was obtained. This dual stereoselectivity is explained by a stereocontrolled acetate attack (trans or cis, respectively) on the allyl group in the catalytic (π-allyl)- palladium intermediate. To further strengthen the mechanism the intermediate (π-ally1)palladium complex was isolated and fully characterized. A stereospecific synthesis of cis- and truns-2-[6- (benzyloxy)-2,4-heptadien-l-yllacetic a cid (cis- and truns-9) followed by stereoselective Pd(I1)- catalyzed chloro- and acetoxylactonization in acetonelacetic acid resulted in highly functionalized fused lactones with control of the relative stereochemistry at four different carbons.
Place, publisher, year, edition, pages
1993. Vol. 58, no 20, 5445-5451 p.
IdentifiersURN: urn:nbn:se:uu:diva-84520DOI: 10.1021/jo00072a029OAI: oai:DiVA.org:uu-84520DiVA: diva2:112428