Abstract
Synthesis of (E)-β,γ-unsaturated acids from aldehydes with malonic acid has been explored under solvent-free conditions. The modified Knoevenagel condensation reaction with N-methyl morpholine (NMM) as catalyst exhibits highly β,γ-regioselectivity and exclusively E-stereoselectivity. A mechanism accounting for both regio- and stereoselectivity has been proposed and preliminarily studied.
Notes
a Yields refer to isolated combined product of β,γ- and α,β-hexenoic acids.
b Determined by 1H NMR analysis of the crude product.
c Ratio of E:Z refers to β,γ-hexenoic acids, and >99:1 means only one isomer was observed.
a Yields refer to isolated combined product of β,γ- and α,β-unsaturated acids.
b Determined by 1H NMR analysis of the crude product.
c Ratio of E:Z refers to β,γ-unsaturated acids, and >99:1 means only one isomer was observed.
d Data in parantheses refer to the results of reaction with Et3N instead of NMM.
a Yields refer to isolated combined product of β,γ- and α,β-isomers.
b Determined by 1H NMR analysis of crude product.
c Ratio of E:Z refers to β,γ-isomers, and >99:1 means only one isomer was observed.