Gas phase thermalisomerizations of twelve acetylenic systems, all of which can in principle undergo two successive pericyclic steps, are described. The substrates, the syntheses and spectroscopic properties of which are presented, are formal derivatives of but-2-yne, with different functional groups in the 1- and the 4-positions. The Cope, Claisen, Claisen ester, retro-ene, 1,5-hydrogen shift, and
Allenes. Part XXVIII. Synthesis of antibiotic lactols and an allenic ester by Claisen rearrangement of prop-2-ynyl vinyl ethers
作者:Donald K. Black、Zacharias T. Fomum、Phyllis D. Landor、Stephen R. Landor
DOI:10.1039/p19730001349
日期:——
Naturally occurring 4-hydroxy-2-vinylbut-2-en-4-olide (V), an allenic analogue [4-hydroxy-3,3-dimethyl-2-vinylidenebutan-4-olide (VII)], and the corresponding aldehyde ester [ethyl 2-(1-formyl-1-methylethyl)buta-2,3-dienoate (VIII)] have been synthesised by a Claisen-type sigmatropic rearrangement of 3-carboxyprop-2-ynyl vinyl ethers.