Cycloaldol Approach to the Isobenzofuran Core of Eunicellin Diterpenes
作者:Yonghai Chai、David A. Vicic、Matthias C. McIntosh
DOI:10.1021/ol034052f
日期:2003.4.1
[reaction: see text] A novel cycloaldol approach to the isobenzofuran core common to many of the eunicellin diterpenes is described. The cycloaldol precursor was prepared by aldol addition of (S)-(+)-carvone and methacrolein followed by etherification to a glycolate ester. Chemoselective enolization of the glycolate ester led to the cycloaldol adduct in high yield and diastereoselectivity. An oxidative
Enantiospecific Synthesis of a Novel Rearranged Eunicellane Diterpenoid by SmI2-Mediated Cyclization
作者:Thomas Lindel、Elisabeth Schöttner、Peter Jones
DOI:10.1055/s-0029-1216990
日期:2009.12
rearranged eunicellane skeleton can be obtained in one step by treatment of an α,β-unsaturated diterpenoid with samariumdiiodide generated in situ in THF. NOESY-based structure analysis revealed the presence of an ansa bridge across a twist-boat six-membered ring. diterpenoids - retro-aldol reaction - samariumdiiodide - isoeunicellane - NOESY-based analysis