- Practical Stereoselective Synthesis of (2E)- and (2Z)-4-Cycloalkylidenebut-2-enoic Acids
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Stereoselective synthesis of α,β-unsaturated esters 7 and 8 was achieved through Horner-Wadsworth-Emmons reaction of β,β -disubstituted α,β-unsaturated aldehydes. Thus, aldehydes 6 undergo olefination with phosphonate carbanion generated from triethyl phosphonoacetate 3 and lithium hydroxide or butyl lithium/DMPU to give (E)-α,β -unsaturated esters 7 with excellent selectivity. The treatment of 6 with the new Horner-Emmons reagents, ethyl(diphenylphosphono)acetate 4a and ethyl (di-o-tolyl-phosphono) acetate 4b in the presence of benzyltrimethyl ammonium hydroxide (Triton B) afforded (Z)-α,β-unsaturated esters 8 with 73-89% selectivity. The esters 7 and 8 were converted to (2E)- and (2Z)-4-cycloalkylidenebut-2-enoic acids 9 and 10, respectively.
- Karagiozov, Stoyan K.,Abbott, Frank S.
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p. 871 - 888
(2007/10/03)
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- VALPROIC ACID ANALOGUES AND PHARMACEUTICAL COMPOSITIONS THEREOF
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Analogues of valproic acid useful in treating neuroaffective disorders including convulsions, bipolar disorder, and migraine headache are disclosed. The analogues are halide substituted analogues, cyclic analogues, and conjugated diene analogues of valproic acid. Pharmaceutical compositions or prodrugs containing the analogues or pharmaceutically acceptable salts thereof are disclosed. Methods of making the compounds and treating mammals with neuroaffective disorders are also disclosed.
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