Synthesis 1989; 1989(2): 123-124
DOI: 10.1055/s-1989-27168
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Improved Synthesis of Methyl Alkoxyacetylenecarboxylates

Francisco Camps* , Josep Coll, Amadeu Llebaria, Josep M. Moretó, Susagna Ricart
  • *Departament de Química Orgànica Biològica, C.I.D, (C.S.I.C), Jordi Girona 18-26, E-08034 Barcelona, Spain
Further Information

Publication History

Publication Date:
17 September 2002 (online)

The title compounds 3a-d can be satisfactorily prepared by the reaction of lithium alkoxyacetylides with methyl chloroformate in tetrahydrofuran at - 78°C, in the presence of a 3.5 molar excess of lithium bromide (based on chloroformate). Moderate to good yields of 3a-d were obtained according to the product stabilities. However, methyl tert-butoxyacetylenecarboxylate (3e) was too unstable to be isolated. The putative dual role of the lithium salt and the formation of substantial amounts of carbonates, observed in its absence, are discussed.

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