4a-Substituted 1,1-dimethyl or 1-carbomethoxy-1-methyl hydrofluorenes carrying various substituents in the aromatic ring could be conveniently synthesized by Pd(0)-catalyzed Heck reaction. The required bromobenzyl-substituted ethylidene cyclohexane substrates were derived from Hagemann's ester (methyl analogue) via condensation with appropriate benzyl bromide, hydrolytic decarboxylation of the ester
Intramolecular Heck reaction strategy for the synthesis of functionalised tetrahydroanthracenes: a facile formal total synthesis of the linear abietane diterpene, umbrosone
作者:Sujaya Sengupta、Ranjan Mukhopadhyay、Basudeb Achari、Asish Kr. Banerjee
DOI:10.1016/j.tetlet.2005.01.021
日期:2005.2
Rapid annulation employing an intramolecular Heck reaction yielded the functionalised 1,1,10-trimethyl-6-methoxy-1,2,3,4-tetrahydroanthracene 4a, a key intermediate for the linear diterpenoid quinone umbrosone (1), and the related compounds 4b-d. A similar strategy was also successfully adopted for the synthesis of the 9-methyl tetrahydroanthracene ester 5 and the tetrahydrodibenzo[a,d]cycloheptene ester 6. (C) 2005 Elsevier Ltd. All rights reserved.