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A Short Synthesis of Allene‐ and [3] Cumulenecarboxylates
Author(s) -
KohlMines Elisabeth,
Hansen HansJürgen
Publication year - 1985
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19850680819
Subject(s) - chemistry , allene , yield (engineering) , toluene , iodide , medicinal chemistry , organic chemistry , catalysis , materials science , metallurgy
Abstract It is shown that carboxylic acids, in the presence of Bu 3 N and 2‐chloro‐1‐methylpyridinium iodide in toluene or CH 2 Cl 2 , react with [(alkoxycarbonyl)methylidene]phosphoranes to yield the corresponding esters of allene carboxylic acids (ef. Scheme 1 and Table 1) . This procedure can also be applied to cinnamic acids which form [3]cumulenecarboxylates in low yield (Table 3) . Under the same conditions 4‐methyl‐2‐pentynoic acid can be transformed into ( 2E )‐4‐chloro‐2,6‐dimethylhepta‐2,4,5‐trienoate (Scheme 4) .