A stereocontrolled synthesis of freelingyne was established by Pd(0)-catalyzedcoupling of vinylhalides with acetylene derivatives, followed by Pd(II)-catalyzed intramolecular stereoselective γ-(Z)-alkylidenebutenolide formation.
Efficient and Stereoselective Synthesis of Freelingyne <i>via</i> Pd-Catalyzed Cross Coupling and Lactonization<sup>1</sup>
作者:Fang Liu、Ei-ichi Negishi
DOI:10.1021/jo971360g
日期:1997.11.1
Z- or E-configurated γ-alkylidenebutenolides from a 2-(trimethylsiloxy)furan and iodomethacrolein - stereoselective synthesis of Z- and E-freelingyne
作者:Frank von der Ohe、Reinhard Brückner
DOI:10.1016/s0040-4039(98)00240-8
日期:1998.4
The gamma-(alpha-hydroxylalkyl)butenolides lk-5 and ul-5 were prepared by Mukaiyama aldol additions between iodoaldehyde 10 and the trimethylsiloxy-substituted furan 6 in the presence of BF3 . OEt2 and ZnBr2, respectively. Couplings of these butenolides with 3-ethynylfuran followed by anti-eliminations of water mediated by DEAD/PPh3 led to Z-freelingyne (Z-11; ds = 92:8) and E-freelingyne (E-11; ds = 98:2). (C) 1998 Elsevier Science Ltd. All rights reserved.