An attractive method for assembling pi-conjugated dienynes with high stereoselectivity was achieved by dehydration reaction of TMS-substituted [3]cumulenols catalyzed by TsOH center dot H(2)O. On the other hand, cycloisomerizations of the corresponding [3]cumulenones catalyzed by gold(I) complexes afford vinyl furans through activation of the cumulenic double bond via a pi-complex, and during the process, deprotonation from an alkyl group on cumulene terminus takes place to induce the isomerization. (C) 2011 Elsevier Ltd. All rights reserved.
Wang EJ,Fu XP,Jie X,et al. Gold and Bronsted acid catalyzed isomerization of [3]cumulenols and [3]cumulenones: efficient syntheses of 1,5-dien-3-ynes and furan derivatives[J]. Tetrahedron Lett.,2011,52(16):1968-1972.
