The Rh(II)- and Cu(II)-catalyzed reactions of N-bis(trimethylsilyl)methyl, N-(2-indolyl)methyl α-diazoamides are investigated to delineate how conformational, steric and electronic factors influence the site- and chemoselectivity of the metallocarbenoid reaction. The N-bis(trimethylsilyl)methyl (N-BTMSM) group is found to be essential in promoting the metallocarbenoid reaction at the N-(2-indol...

Four new iridoids structurally related to gelsemide (5) were isolated from two Loganiaceous plants, Gelsemium elegans and G. rankinii. Among them, GEIR-1 (1) has a novel tetracyclic caged structure.

The MeOH extract from dried aerial parts of Oxypetalum caeruleum (Apocynaceae) plants yielded seventeen compounds, including four new tetracyclic triterpenoids, one pregnane glycoside, two lignane glycosides, and ten known compounds. structures the compounds were established using NMR, MS spectroscopic analysis chemical evidence.

Five novel chromones (1,4-benzopyran-4-ones), among which three are tetracyclic and one contains a sulfonyl group, have been isolated from an Ascomycete, Chaetomium quadrangulatum, as monoamine oxidase inhibitory features, and named chaetoquadrins A (1)-E (5).

An arene-terminated epoxy olefin cyclization was promoted by a water-tolerant Lewis acid to give tri- and tetracyclic 3beta-hydroxy terpenoids and steroid derivatives in 57 and 37% yields, respectively, per new formed ring up to 75%.

The enantioselective synthesis of advanced tetracyclic precursors of madangamine D, bearing rings ABCD of this alkaloid, is reported. The saturated 14-membered ring is assembled from functionalized diazatricyclic intermediates following either ring-closing metathesis or macrolactamization strategies.

‎in this paper we introduce mixed unitary cayley graph $m_{n}$‎ ‎$(n>1)$ and compute its eigenvalues‎. ‎we also compute the energy of‎ ‎$m_{n}$ for some $n$‎.

An efficient access to the tetracyclic-fused quinoline systems, 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives 4a-l, is described, involving the intramolecular Friedel-Crafts acylation reaction of 2-(phenoxymethyl)-4-phenylquinoline-3-carboxylic acid derivatives 3a-l aided by the treatment with PPA (polyphosphoric acid) or Eaton's reagent. The required starting compound (2) wa...