80674-54-0Relevant academic research and scientific papers
Iodine(III)-Mediated Contraction of 3,4-Dihydropyranones: Access to Polysubstituted γ-Butyrolactones
Dagenais, Robin,Lussier, Tommy,Legault, Claude Y.
, p. 5290 - 5294 (2019/09/03)
Functionalized γ-butyrolactones are privileged structures in the field of medicinal chemistry; they are found in numerous natural products and synthetic compounds with diverse biological activities. The oxidative ring contraction of 3,4-dihydropyran-2-one derivatives represents a promising yet underappreciated strategy to access these compounds. To the best of our knowledge, very few examples of this strategy have been reported, with limited investigation of the influence of stereogenic centers on the starting dihydropyranones. We investigated the iodine(III)-mediated contraction of a representative set of dihydropyranone derivatives. The method gives rapid access to functionalized γ-butyrolactones in good yields. The reaction scope was investigated, and the method was found to support various levels of substituents, even enabling access to sterically congested quaternary centers. The stereoselectivity was investigated using chiral substrates and a chiral iodine(III) reagent.
Additions of Carboxylic Acid Dianions to α,β-Unsaturated Carbonyl Compounds - Control of the 1,2-/1,4-Regioselectivity by Steric Substituent Effects
Mulzer, Johann,Bruentrup, Gisela,Hartz, Georg,Kuehl, Uwe,Blaschek, Ursula,Boehrer, Gerald
, p. 3701 - 3724 (2007/10/02)
Dilithium carboxylic acid dianions 1 attack α,β-unsaturated aldehydes (2) 1,2-regiospecifically with formation of the unsaturated β-hydroxy carboxylic acids 3/4.Additionally, the addition of the phenylacetate dianion 1a can be conducted to the threo-isomer with high selectivity by reversible reaction. - α,β-Enones (8) add 1 irreversibly in 1,2- and 1,4-position.Depending on the substitution pattern, the whole range from pure 1,2- to pure 1,4-adduct is covered.The influence of the 1-counterion M and of the solvent is significant; the 1,4-portion increases with the complexing effect of M and with the Lewis-basicity of the solvent.
