US EPA

5018056 

Journal Article 

A novel approach to oxazole-containing diterpenoid synthesis from plant roots: salviamines E and F 

Narita, K; Fujisaki, N; Sakuma, Y; Katoh, T 

2019 

1 

Organic and Biomolecular Chemistry
ISSN: 1477-0520
EISSN: 1477-0539 

Royal Society of Chemistry 

17 

3 

655-663 

English 

30575839 

10.1039/c8ob03030h 

WOS:000458578900026 

https://www.proquest.com/scholarly-journals/novel-approach-oxazole-containing-diterpenoid/docview/2167383823/se-2?accountid=171501
Exit
 

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); (ii) the construction of a tricyclic phenanthrene ring by acid-induced cyclization of a naphthalene derivative with a homoprenyl side chain; (iii) the formation of an oxazole ring by nucleophilic ring closure of a 2-aminophenylene-1,4-diyl-diformate or -diacetate moiety and (iv) Friedel-Crafts acetylation at the C13 position of the tetracyclic intermediates to obtain the two target molecules, salviamines E and F. To the best of our knowledge, salviamine synthesis is reported here for the first time. 

Chemistry; Naphthalene; Alkaloids; Intermediates; Plant roots; Oxazole; Acetylation; Phenanthrene; Coupling (molecular); Naphthol; Coupling; Chemical synthesis; Nuclear magnetic resonance--NMR