Stereoisomeric flavor compounds. 20. Structure and properties of .gamma.-lactone enantiomers

Artificial Biocatalytic Linear Cascades to Access Hydroxy Acids, Lactones, and α- and β-Amino Acids

“…ɛ-Caprolactone, on the other hand, biodegradable polymers, such as polycaprolactone [6 The chemical synthesis of these compounds usua yields, toxic or otherwise hazardous reagents, and imp neither "green" nor atom-economic [70][71][72][73].…”

“…The chemical synthesis of these compounds usually invo yields, toxic or otherwise hazardous reagents, and impractical neither "green" nor atom-economic [70][71][72][73]. Hence, bioca become a useful tool in the preparation of lactones, as they and yield-reducing isolation and purification of intermedia minimum.…”

“…The chemical synthesis of these compounds usually involves a large number o yields, toxic or otherwise hazardous reagents, and impractical reaction conditions, neither "green" nor atom-economic [70][71][72][73].…”

γ(δ)-Thionolactones - Enantioselective Capillary GC and Sensory Characteristics of Enantiomers

“…Whereas c-lactones are important aroma components of many fruits, d-lactones can also be detected in dairy products and other fermented foods [1]. Owing to their importance as pleasant and widespread natural aroma compounds, the sensory properties of c(d)-lactone enantiomers as well as their stereodifferentiation (via diastereomers) were investigated [2,3] already before chiral polyacrylamide was used for the direct LC separation of c(d)-lactones [4]. A real breakthrough in direct enantio-GC analysis occurred when modified cyclodextrins became available as chiral stationary phases.…”

Cooperative Catalysis in Multicomponent Reactions: Highly Enantioselective Synthesis of γ‐Hydroxyketones with a Quaternary Carbon Stereocenter

“…Optically active g-hydroxy carboxylic acid derivatives are key intermediates and building blocks in the synthesis of natural products and pharmaceuticals. [8] Significant efforts have already been made in the preparation of chiral g-hydroxy carboxylic acid derivatives; [9] we now add an efficient method for the construction of such a framework with contiguous quaternary and trisubstituted stereogenic carbon centers. [10] In summary, we have developed an enantioselective three-component reaction of diazo compounds with H 2 O and a,b-unsaturated 2-acyl imidazoles in the presence of [Rh 2 (OAc) 4 ], (S)-tBu-box-Zn(OTf) 2 , and TsOH.…”