Chemosystematics of the lauraceae

Recent advances and applications of reductive desulfurization in organic synthesis

Stereoselective synthesis of tetrahydrofuran lignans via BF(3) x OEt(2)-promoted reductive deoxygenation/epimerization of cyclic hemiketal: synthesis of (-)-odoratisol C, (-)-futokadsurin A, (-)-veraguensin, (+)-fragransin A(2), (+)-galbelgin, and (+)-talaumidin.

Acid-catalyzed cyclizations of E,E-dibenzylidenesuccinate esters have been developed as an efficient synthetic route to 1-aryl-1,2-dihydronaphthalenes. This reaction has been used in the synthesis of the naturally occurring lignans (+/-)-cagayanin and (+/-)-galbulin.

Acid-Catalyzed Cyclization of 2,3-Dibenzylidenesuccinates: Synthesis of Lignans (±)-Cagayanin and (±)-Galbulin

From a MeOH extract of the aerial part of Piper futokadsura, the tetrahydrofuran lignans, futokadsurin A [(7S,8S,7′S,8′R)-3,4,3′-trimethoxy-4′-hydroxy-7,7′-epoxylignan], futokadsurin B [(7R,8R,7′R,8′S)-3,4-dimethoxy-3′,4′-methylenedioxy-7,7′-epoxylignan], and futokadsurin C [(7R,8R,7′S,8′S)-3,4-methylenedioxy-3′,4′-dimethoxy-7,7′-epoxylignan] were isolated, together with nine known neolignans. In addition, L-tryptophan, pellitorine, phytol, elemicin, and 1,2,4-trimethoxyphenyl-5-aldehyde were isolated. The structures of the new compounds were elucidated using spectroscopic methods. These lignans inhibited nitric oxide production by a murine macrophage-like cell line (RAW 264.7), which was activated by lipopolysaccharide and interferon-γ.

/pdf/neolignans-from-piper-futokadsura-and-their-inhibition-of-1128wmeulw.pdf

N. S. Crossley

Papers

275. Naturally occurring oxygen heterocyclics. Part XI. Veraguensin

1164. Studies in organic sulphur compounds. Part XVII. The synthesis of previously inaccessible acylated enamines by desulphurisation of thiazolidines