Diastereoselective synthesis of tetrahydrofuran-containing fragments by the permanganate oxidation of 1,5,9-trienes
作者:Richard C. D. Brown、Robert M. Hughes、John Keily、Anne Kenney
DOI:10.1039/b004307i
日期:——
The permanganate oxidation of several readily accessible
1,5,9-trienes occurs regioselectively to provide very short
diastereoselective routes to substituted octahydro-2,2′-bifuranyl
systems.
A method for the synthesis of bis-tetrahydrofuranyl annonaceous acetogenins, including the natural products and analogs thereof, is provided which proceeds by the Pd-mediated coupling of a bis-tetrahydrofuranyl-subunit comprising a terminal alkyne, with a (C4)-hydroxybutenolide subunit comprising a terminal vinyl iodide, followed by selective reduction of the resulting enyne.
Catalytic diastereo- and positionselective oxidative mono-cyclization of 1,5,9-trienes and polyenes
作者:Sabrina Göhler、Christian B. W. Stark
DOI:10.1039/b702877f
日期:——
Ruthenium tetroxide (1 mol%) has been used as a catalyst for the oxidative mono-cyclization of 1,5,9-trienes and polyenes. The poly-unsaturated substrates underwent mono-cyclization with a high degree of diastereo- and positionselectivity to produce mono-tetrahydrofuran diols with a varying degree of unsaturation. Up to four new stereogenic centers were created in this single step transformation. The remarkable positionselectivity appears to be a result of relative electronic properties of the double bonds within the polyolefinic substrates in conjunction with conformational constraints.
Oxidative Cyclization Reactions of Trienes and Dienynes: Total Synthesis of Membrarollin
作者:Claire L. Morris、Yulai Hu、Geoff D. Head、Lynda J. Brown、William G. Whittingham、Richard C. D. Brown
DOI:10.1021/jo802012a
日期:2009.2.6
alkene geometry and methodology for the closure of the second ring. The threo-cis-threo-cis-erythro stereochemical arrangement is embodied within the bis-THF core units of a number of Annonaceous acetogenins including membrarollin, while trilobacin has a threo-cis-erythro-trans-threo configured core. As an application of the selective oxidative cyclization approach, a totalsynthesis of membrarollin was
Synthesis of <i>cis-</i> and <i>trans</i>-2,5-Disubstituted Tetrahydrofurans by a Tandem Dihydroxylation-S<sub>N</sub>2 Cyclization Sequence
作者:James A. Marshall、Jesse J. Sabatini
DOI:10.1021/ol051507n
日期:2005.10.1
[reaction: see text] Dihydroxylation of delta- and epsilon-mesyloxy alpha,beta-unsaturated esters proceeds with in situ cyclization to afford 2,5-disubstituted and 2,3,5-trisubstituted tetrahydrofurans.