Highly Diastereoselective Preparation of anti-1,2-Diols by Catalytic Addition of Alkynylsilanes to α-Silyloxyaldehydes
摘要:
The catalytic, diastereoselective coupling of alpha-silyloxy aldehydes and alkynylsilanes catalyzed by a nickel(0) N-heterocyclic carbene complex provides an effective entry to anti-1,2-diols. The scope of couplings and extent of diastereoselection are excellent across a range of substrates.
A new method for stereospecific construction of the allylic alcohol moiety of prostaglandins, based on application of optically active α-hydroxy aldehydes, is described. In the presence of BF3 .Et2O, lithiated sulphones prepared from Corey aldehyde, and carbonyl compounds give t or only their traces were formed. The addition products , in the form of benzoates, mesylates or free alcohols, were subjected
Total Synthesis of Aigialomycin D: Surprising Chemoselectivity Dependence on Alkyne Structure in Nickel-Catalyzed Cyclizations
作者:Christa C. Chrovian、Beth Knapp-Reed、John Montgomery
DOI:10.1021/ol702961v
日期:2008.3.1
The totalsynthesis of aigialomycin D was carried out using a nickel-catalyzed ynal macrocyclization as a key step. This key step allowed macrocycle assembly and formation of a disubstituted alkene and a secondary hydroxyl stereocenter in a single step, although the stereocenter was formed unselectively. An interesting side reaction involving five-membered-ring synthesis by an aldehyde/styrene cyclization
1,3-allylic transposition of the C-9 hydroxyl group of compound 13 has allowed the first total synthesis of J(2) isoprostane (1), a recently discovered member of the growing isoprostane family. This elusive compound opens up numerous new avenues for the molecular biology of cyclopentenoneprostaglandins which are endowed of intriguing biological effects such as antitumor, antiinflammatory, and antiviral
Transformation of the diol 1 via epimeric sulphones 7 to PGF2α, is described. Alkylation of lithiated sulphones 7 with aldehydes 8a, 8b or 8c in the presence of BF3 efficiently gives corresponding adducts.
First Total Synthesis of A<sub>2</sub> Isoprostane
作者:Giuseppe Zanoni、Alessio Porta、Giovanni Vidari
DOI:10.1021/jo025652f
日期:2002.6.1
allowed the first total synthesis of A(2) isoprostane (1), a recently discovered member of the growing isoprostane family. This elusive compound opens up numerous new avenues for the molecular biology of cyclopentenoneprostaglandins, which are endowed of intriguing biological effects such as antitumor, antiinflammatory, and antiviral activities.