1,<i>n</i>-Rearrangement of Allylic Alcohols Promoted by Hot Water: Application to the Synthesis of Navenone B, a Polyene Natural Product
作者:Pei-Fang Li、Heng-Lu Wang、Jin Qu
DOI:10.1021/jo5004086
日期:2014.5.2
n-rearrangement (n = 3, 5, 7, 9) of allylic alcohols. In some cases, the rearrangement reactions joined isolated C–C double or triple bonds to generate conjugated polyene or enyne structure motifs. We used the 1,3-rearrangement reaction of an allylic alcohol in hot water as part of an attractive new strategy for construction of the polyene naturalproduct navenone B by iterative use of a Grignard reaction
Size-Exclusion Borane-Catalyzed Domino 1,3-Allylic/Reductive Ireland-Claisen Rearrangements: Impact of the Electronic and Structural Parameters on the 1,3-Allylic Shift Aptitude
reductive Ireland–Claisenrearrangement through borane‐mediated hydrosilylation is reported. The method employs a borane catalyst with a special structural design and affords access to synthetically relevant products with high diastereoselectivity. Depending on electronic and structural parameters, the reaction can be coupled with a 1,3‐allylic shift, thus the valence isomer of the Ireland–Claisen product
(<i>Z</i>)-Selective Enol Triflation of α-Alkoxyacetoaldehydes: Application to Synthesis of (<i>Z</i>)-Allylic Alcohols via Cross-Coupling Reaction and [1,2]-Wittig Rearrangement
corresponding (Z)-vinyl triflates was achieved by treatment with phenyl triflimide and DBU. The stereochemistry was explained by the “syn-effect,” which was attributed primarily to an σ → π* interaction. The β-alkoxy vinyl triflates obtained were applied to the stereoselective synthesis of structurally diverse (Z)-allylic alcohols via transition metal-catalyzed cross-coupling reaction and [1,2]-Wittig
Tandem Benzylic Oxidation/Dihydroxylation of<i>α</i>-Vinyl- and<i>α</i>-Alkenylbenzyl Alcohols
作者:Rodney A. Fernandes、Pullaiah Kattanguru
DOI:10.1002/hlca.201400143
日期:2015.1
A de novo tandembenzylicoxidativedihydroxylation of α‐vinyl‐ and α‐alkenylbenzyl alcohols has been developed to give α,β‐dihydroxypropiophenones (=2,3‐dihydroxy‐1‐phenylpropan‐1‐ones) and α,β‐dihydroxyalkyl phenones. This method was shown to be substrate‐selective and specific for the oxidation of benzylicalcohols.
1,2-Metallate rearrangements involving reaction of 1-metallated glycals with organolithium reagents under copper(I) mediation give alkenylpolyol chains in 45-91% yield (19 examples). The reaction was applied to a formal synthesis of KRN7000 as well as a synthesis of a Δ5,6-ceramide derivative. 1,2-metallate rearrangement - retro-[1,4]-Brookrearrangement - 1-metallated glycals - cuprates - organolithiums