Synthetic studies to highly functionalised B ring labdanes
摘要:
Several 6,7-dioxygenated (cis or trans) labdanes have been synthesised starting front sclareol. A new strategy that allows the obtention of diols alpha-cis as well as beta-cis of trans is described. In particular, the syntheses of three natural highly functionalised labdanes in the B rings of 2, 3 and 4 with different side chains are reported. The syntheses have permitted to Correct the proposed Structure for one of them. (C) 2008 Elsevier Ltd. All rights reserved.
Bioactive Metabolites from the South African Marine Mollusk <i>Trimusculus costatus</i>
作者:Albert W. W. van Wyk、Christopher A. Gray、Catherine E. Whibley、Omolaja Osoniyi、Denver T. Hendricks、Mino R. Caira、Michael T. Davies-Coleman
DOI:10.1021/np070612y
日期:2008.3.1
A reinvestigation of extracts of the endemic South African intertidal limpet Trimusculus costatus yielded the known labdane diterpenes 6 beta,7 alpha-diacetoxylabda-8,13E-dien-15-ol (1) and 2 alpha,6 beta,7 alpha-triacetoxylabda-8,13E-dien-15-ol (2) and three new metabolites, 6 beta,7 alpha,15-triacetoxylabda-8,13E-diene (3), 3 alpha,11-dihydroxy-9,11-seco-cholest-4,7-dien-6,9-dione (4), and cholest-7-en-3,5,7-triol (5). Chiral derivatization and X-ray analysis were used to confirm the labdane absolute configuration of 2. Compounds 1, 2 and 4 exhibited moderate activity (3-25 mu M) against the WHCO1 human esophageal cancer cell line.
Synthetic studies to highly functionalised B ring labdanes
Several 6,7-dioxygenated (cis or trans) labdanes have been synthesised starting front sclareol. A new strategy that allows the obtention of diols alpha-cis as well as beta-cis of trans is described. In particular, the syntheses of three natural highly functionalised labdanes in the B rings of 2, 3 and 4 with different side chains are reported. The syntheses have permitted to Correct the proposed Structure for one of them. (C) 2008 Elsevier Ltd. All rights reserved.