A CONVENIENT METHOD FOR THE SYNTHESIS OF 4-CHLORO-3-ALKENOIC ACID. A NEW USEFUL SYNTHETIC BLOCK FOR 4-OXOALKANOIC AND 4-OXO-2-ALKENOIC ACIDS
作者:Masatoshi Kawashima、Tamotsu Fujisawa
DOI:10.1246/cl.1984.1851
日期:1984.10.5
Easily available material, β-(1-chlorovinyl)-β-propiolactone reacted with organocopper reagents to afford 4-chloro-3-alkenoic acids in high yields. The acids were easily transformed into two kinds of useful carboxylic acids such as 4-oxoalkanoic and 4-oxo-(E)-2-alkenoic acids leading to various natural products.
Ligand Control of Palladium‐Catalyzed Site‐Selective α‐ and γ‐Arylation of α,β‐Unsaturated Ketones with (Hetero)aryl Halides
作者:On Ying Yuen、Chau Ming So
DOI:10.1002/anie.202010682
日期:2020.12.21
describes the first palladium‐catalyzed, site‐selective α‐ and γ‐arylation of α,β‐unsaturated ketones with (hetero)arylhalides. A wide range of hetero(aryl)halides coupled with α,β‐unsaturated ketones, and transformation into the arylated products proceeded with excellent to good yields. The site selectivity of the reaction is switchable by simply changing the phosphine ligand to access either α‐arylated
Ring expansion of succinoin derivatives. New synthetic routes to cyclopentenones
作者:Eiichi Nakamura、Jun-ichi Shimada、Isao Kuwajima
DOI:10.1039/c39830000498
日期:——
Acid-catalysed ringexpansion reactions of cyclobutane derivatives bearing a vicinal substituted-diol group give α-aryl and α-vinyl substituted cyclopentenones in good yields.
Conjugated addition of primary nitroalkanes to α,β-unsaturated ketones or α,β-unsaturated esters, in the presence of two equivalents of DBU, allows the one-pot prepration of γ-diketones or γ-keto esters, respectively. When 2-aryl-1-nitroethane derivatives are employed as starting nitroalkanes in the reaction with α,β-unsaturated ketones, the one-pot formation of cyclopentenones is observed.