General route to 4a-methylhydrofluorene diterpenoids: Total syntheses of (±)-taiwaniaquinones D and H,(±)-taiwaniaquinol B,(±)-dichroanal B, and (±)-dichroanone

M Banerjee, R Mukhopadhyay, B Achari…

Index: Banerjee, Mainak; Mukhopadhyay, Ranjan; Achari, Basudeb; Banerjee, Asish Kr. Journal of Organic Chemistry, 2006 , vol. 71, # 7 p. 2787 - 2796

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Citation Number: 72

Abstract

A general and convergent route for the synthesis of the 4a-methylhydrofluorene diterpenoids has been established through a common hexahydrofluorenone intermediate (10) obtained via Pd (0)-catalyzed reductive cyclization of a substituted 2-(2-bromobenzyl) methylene cyclohexane (13). The strategy has been successfully utilized for the synthesis of (±)- taiwaniaquinones D (3) and H (5),(±)-taiwaniaquinol B (1),(±)-dichroanal B (7), and (±)- ...