42969-18-6Relevant academic research and scientific papers
A [3.3]Sigmatropic rearrangement of α,β-unsaturated Fischer chromium carbenes: Synthesis of alkynol and dienol esters
S?derberg, Bj?rn C.,O'Neil, Shannon N.,Chisnell, Angela C.,Liu, Jian
, p. 5037 - 5044 (2000)
A novel [3.3]sigmatropic rearrangement of in situ formed α,β- unsaturated Fischer acyloxy carbenes forming alkynol esters is described. For example, reaction of tetramethylammonium pentacarbonyl(1-oxo-2- butenyl)chromate(1-) (4) with 4-methoxybenzoyl chloride gave 2-methyl-3- butyn-2-yl 4-methoxybenzoate (8) in 32% yield. In addition to the rearrangement products, dienol esters formed by a formal β-hydride elimination-reductive elimination sequence were usually isolated. In the above example, 3-methylbuta-1,3-dien-1-yl 4-methoxybenzoate (9) was obtained (16%) as the side product. (C) 2000 Elsevier Science Ltd. All rights reserved.
