Gold(I)‐Catalyzed Furan‐yne Cyclizations Involving 1,2‐Rearrangement: Efficient Synthesis of Functionalized 1‐Naphthols and Its Application to the Synthesis of Wailupemycin G

Abstract

Gold-catalyzed cascade cyclization/1,2-rearrangement of 1-(2-furanyl)phenyl propargyl alcohols has been developed, which provides a rapid and efficient access to multisubstituted 1-naphthols bearing an enal or enone moiety with high stereoselectivity. The (Z)- or (E)-stereochemistry can be easily controlled by choosing protected- or non-protected substrates. The utility of the methodology has been illustrated in the first total synthesis of wailupemycin G.

Oxygen as a Heteroatom in Propargylic Alcohols: Reactivity, Selectivity, and Applications

“…The proposed mechanism is shown in Scheme 12. Initially, Hg(OTf) 2 coordinate with alkyne 33, and generate oxonium cation intermediate 35 via involvement of the acetyl group in [3,3] In 2014, Reddy and co-workers reported, iodo Meyer-Schuster rearrangement (MSR) of phenoxy propargyl alcohols for the synthesis of α-iodo-α, β-unsaturated esters (Scheme 13). [20a] These are the very important subunits for the synthesis of highly substituted olefins, either reduction of ester moiety or by the metal-catalyzed cross coupling reactions (Suzuki, Sonagashira etc.)…”

“…The applications of propargylic alcohols [1] in many useful transformations, significant utilization in total synthesis, [2][3][4][5][6][7]9] and in construction of many heterocyclic compounds [8][9] and their derivatives have gained much attention and have been extensively investigated. Recent developments on the chemistry of propargylic alcohols and their derivatives disclosed a variety of highly efficient Lewis acid-catalyzed cascade reactions based on Meyer-Schuster rearrangement [10][11][12] (MSR) of propargylic alcohols, [3,3] rearrangement of propargylic acetates and intramolecular cyclization of propargylic alcohols, tethered with nucleophiles. The classical MSR of propargylic alcohols (A, Scheme 2, Eq.…”

“…The carbocation intermediates and precursors are shown in Scheme 1. Based on literature reports and recent advancement in synthetic organic chemistry, the presented review will cover the versatile productivity of oxygen-containing propargylic alcohols under the following subtitles-(i) Meyer À Schuster rearrangement and [3,3] rearrangement (ii) α-addition and (iii) intramolecular cyclization.…”

Gold Catalysis for Heterocyclic Chemistry: A Representative Case Study on Pyrone Natural Products

“…[88] Arecent approach to wailupemycin C(98)illustrates the power of p-acid catalysis;i nt his case,agold-catalyzed rearrangement was cleverly utilized to prepare the polysubstituted naphthol derivative 96 (Scheme 22). [89] Elaboration into ketoester 97 set the stage for the gold-catalyzed cyclization, which furnished the corresponding 2-pyrone in high yield. Hydrogenolytic cleavage of the benzyl protecting groups completed the total synthesis of this particular secondary metabolite derived from the marine bacterium strain Streptomyces maritimus.…”

Gold‐Katalyse für die Heterocyclenchemie: eine repräsentative Fallstudie zu Naturstoffen der Pyron‐Reihe

“…Die Vorzüge der π‐Säure‐Katalyse treten ferner an einem jüngst publizierten Zugang zu Wailupemycin C ( 98 ) hervor, wobei zunächst eine Gold‐katalysierte Umlagerung zum Aufbau des polysubstituierten Naphthol‐Derivats 96 genutzt wurde (Schema ) . Der weiteren Umsetzung zu Ketoester 97 folgte die Bildung des Heterocyclus in guter Ausbeute.…”