General route to 4a-methylhydrofluorene diterpenoids: total syntheses of (+/-)-taiwaniaquinones d and h, (+/-)-taiwaniaquinol B, (+/-)-dichroanal B, and (+/-)-dichroanone.
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 (+/-)-dichroanone (8).
Medicinal Chemistry Division, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata-700 032, India.
Mainak
M
Banerjee
Ranjan
R
Mukhopadhyay
Basudeb
B
Achari
Asish Kr
AK
Banerjee
D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
D004224:Diterpenes; C516090:dichroanal B; C516091:dichroanone; C505702:taiwaniaquinol B; C516089:taiwaniaquinone D; C516088:taiwaniaquinone H