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Functionally substituted vinyl carbanions, 44. Synthesis of odd‐numbered 13‐crown‐4 derivatives possessing a functional group and their application in C ‐lithiation of acrylates
Author(s) -
Jatzke Harald,
Schmidt Richard R.
Publication year - 1991
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.1991199101129
Subject(s) - chemistry , carbanion , deprotonation , lithium (medication) , medicinal chemistry , kinetic control , base (topology) , quenching (fluorescence) , derivative (finance) , alkoxy group , potassium , catalysis , organic chemistry , ion , alkyl , medicine , mathematical analysis , mathematics , endocrinology , physics , quantum mechanics , financial economics , economics , fluorescence
The synthesis of symmetrically hydroxy‐substituted 13‐crown‐ 4 derivatives 2 and 3 is reported. To this end, diol 7 is first deprotonated with potassium tert ‐butoxide and then treated with ditosylate 6 in the presence of lithium perchlorate as a template. Base‐catalyzed addition of 2 and 3 to methyl propiolate affords β‐alkoxy‐substituted acrylates 1a and 1b , respectively. Treatment of 1a with LDA in THF generates the β‐ C ‐lithiated species 1a ‐A as indicated by quenching with CH 3 OD and reaction with propanal; thus, β‐deutero derivative 1a ‐(β‐D) and tetronate 4a , respectively, are obtained. Competition experiments between 1a and methyl β‐methoxyacrylate ( 1c ) with LDA in THF exhibit for 1a a higher thermodynamic but practically the same kinetic acidity.