In this study, salviamines E and F, which are structurally unique abietane-type diterpene alkaloids containing an oxazole ring, were efficiently synthesized from a known molecule, 5,7,8-trimethoxy-1-naphthol. The synthetic sequence involves the following crucial steps: (i) the assembly of a carbon skeleton by coupling a six-carbon homoprenyl unit with a naphthalene moiety (Kumada–Tamao–Corriu coupling);
The first total synthesis of (+/-)-lantalucratins A and B is described. Introduction of an alkyl side chain at the 6-position was proceeded by directed ortho-lithiation and subsequent alkylation reaction to afford 6-alkyl-5,7,8-trimethoxy-1-naphthol as a synthetically important intermediate for (+/-)-lantalucratins A and B in excellent yield with complete regioselectivity. The 1,2-naphthoquinone fused five-membered cyclic ether framework was constructed directly from 3-hydroxyallcyl-naphthalenes by oxidative intramolecular cyclization reaction with diammonium cerium(IV) nitrate. (+/-)-Lantalucratins A and B were obtained in 69% and 45% overall yields, respectively. (C) 2013 Elsevier Ltd. All rights reserved.
Giles, Robin G. F.; Hughes, Andrew B.; Sargent, Melvyn V., Journal of the Chemical Society. Perkin transactions I, 1991, # 6, p. 1581 - 1587
作者:Giles, Robin G. F.、Hughes, Andrew B.、Sargent, Melvyn V.
DOI:——
日期:——
Synthesen in der Naphthalinreihe: Methoxylierte Tetralone und Naphthole