Three-step synthesis of oxylipins from D. loretense
作者:Shreyosree Chatterjee、Gayan A. Abeykoon、Jason S. Chen
DOI:10.1016/j.tetlet.2019.06.040
日期:2019.7
A three-step convergent synthesis of an immunostimulatory oxylipin was developed using an olefin cross metathesis approach. The alkene fragments were prepared in two steps from commercially available starting materials with high stereoselectivity. In particular, an organocatalytic aldehyde α-oxygenation gave high enantioselectivity and yield using as little as 2 mol% catalyst. This synthesis represents
Stereoselective convergent total synthesis of oxylipins
作者:Rodney A. Fernandes、Sandhya S. Yadav、Sanjita Moharana
DOI:10.1039/d4ob00282b
日期:——
We synthesized stereoselectively four stereoisomers of oxylipins (1a–d) by a convergent approach based on chiral catalysis. The synthetic approach involved sequential assembly of two key fragments – ene-diol and allyl alcohol – for an intended convergent cross-metathesis reaction to join these fragments. The key steps include Sharpless kinetic resolution, asymmetric dihydroxylation and Grubbs cross-metathesis
Diastereo- and Enantioselective <i>anti</i>-Alkoxyallylation Employing Allylic <i>gem</i>-Dicarboxylates as Allyl Donors via Iridium-Catalyzed Transfer Hydrogenation
作者:Soo Bong Han、Hoon Han、Michael J. Krische
DOI:10.1021/ja9097675
日期:2010.2.17
Enantioselective transfer hydrogenation of gem-dibenzoate le in the presence of aromatic. alpha,beta-unsaturated, or aliphatic aldehydes 2a-i mediated by isopropyl alcohol and employing a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid, and (R)-SEGPHOS delivers products Of alkoxyallylation 3a-i, 4a, 4e, 4f, and 4i in good isolated yields (62-82%) with good to excellent diastereoselectivities (7:1 to 18:1 dr) and exceptional enantioselectivities (90-99% ee). This protocol provides an alternative to the Use of premetalated nucleophiles in carbonyl alkoxyallylation.