Novel synthesis of flavour quality γ‐lactones

Abstract

The cyclization of 3-alkenoic acids with 80% sulphuric acid in the synthesis of γ γ γ γ γ-lactones is always associated with fumes of sulphur dioxide gas and traces of cyclopentenones. The cyclopentenones formed during the reaction give off-odours to the γ γ γ γ γ -lactones formed. Two catalysts, p-toluene sulphonic acid and o-phosphoric acid, with a catalytic amount of perchloric acid, were tried in the lactonization reaction to obtain γ γ γ γ γ -lactones in high yields, and the reaction was free from sulphur dioxide gas fumes and cyclopentenones. A comparison of these catalysts with 80% sulphuric acid in the synthesis of γ γ γ γ γ -lactones was also made.

Chemoenzymatic Synthesis of Enantiomeric, Bicyclic δ-Halo-γ-lactones with a Cyclohexane Ring, Their Biological Activity and Interaction with Biological Membranes

“…Lactones are cyclic esters which are detected in plants and animals. The natural lactones isolated from fruits and essential oils can be used as fragrance components, like jasmine lactone or as a flavor in the food industry (δ-decalactone) [1][2][3]. Those compounds can also be pheromones [4,5] or antifeedants [6][7][8] but the largest interest is put in their antimicrobial and cytotoxic potential.…”

Synthesis of 7-functionalized γ-lactones from furfural

“…Gamma lactones are widely distributed in nature. They are an important class of compounds found in both natural and synthetic flavours and fragrances 2,3 . They have been also reported to exhibit biological activities such as cytotoxicity, pheromone activity and anti-feedant activity.…”

An Expedient Synthesis of Olfactory Lactones by Intramolecular Hydroacylalkoxylation Reactions

“…Simple Brønsted acids (such as H 2 SO 4 ) and superacids (e.g. TfOH10) can be effective for certain intramolecular cyclizations of alkenoic acids, and have been used for the synthesis of olfactory γ‐lactones 11. However, applications are limited by their corrosive nature, which is aggravated by high temperatures needed for these reactions.…”