ABSOLUTE CONFIGURATIONS OF QUERCUS LACTONES, (3S,4R)- AND (3S,4S)-3-METHYL-4-OCTANOLIDE, FROM OAK WOOD AND CHIROPTICAL PROPERTIES OF MONO-CYCLIC γ-LACTONES

Abstract

Absolute configurations of Quercus lactones were investigated by studying paramagnetic shifts of PMR spectra and the chemical correlation with 2-hydroxyhexanoic acid of known configuration. Chiroptical properties of several mono-cyclic γ-lactones were also studied.

Screening of a polar extract of Paeonia rockii: Composition and antioxidant and antifungal activities

“…The HRESIMS of 1 showed a major ion peak at m/z 159.2915 [M+H] + consistent with the molecular formula C 8 H 14 O 3 . The UV spectrum suggested the presence of a ␥-lactone ring (Masuda and Nishimura, 1981) as determined by peak with max at 205 nm. The 1 H NMR spectrum (Table 1) displayed signals for an oxymethylene group at ı 3.40 (1H, m) and 3.54 (1H, q, J = 6.5, m), a methine proton adjacent to two heteroatoms as suggested by its low-field chemical shift (ı 4.99, 1H, dd, J = 2 and 6.2 Hz), and a terminal methyl at ı 0.95 (3H, t, J = 6.9 Hz).…”

Synthesis, odour characteristics and antibacterial activities of the stereoisomeric forms of whisky lactone and its thiono analogues

“…). The absolute configurations of the natural trans ‐ and cis ‐ 1 were determined to be (3 S ,4 R ) and (3 S ,4 S ), respectively . Natural lactones having general structure 1 were identified in oak wood, which is used for barrels to age such alcoholic beverages .…”

Efficient Syntheses of Traumatic Lactone and Rhizobialide

“…Molecules containing the γ‐butyrolactone moiety occur extensively in nature and many of them have potentials as lead drug compounds or fine chemicals that release a unique fragrance . Traumatic lactone 1 , γ‐(7‐carboxyheptyl)‐γ‐butyrolactone (Figure ), was isolated by Masamune from phaseolus vulgaris ‘Beni‐kintoki’ .…”