Precursors to oak lactone. Part 2: Synthesis, separation and cleavage of several β-d-glucopyranosides of 3-methyl-4-hydroxyoctanoic acid

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

“…Yield: 0.072 g, 92%; Colorless oil; [α] 20 D = +83.6 [ c = 1.0, MeOH, 99% e.e., lit[α] D = +100 ( c = 0.48, MeOH)] . IR (NaCl): cm ‐1 2960 (CH 3 ), 2934, 2860 (CH 2 ), 1774 (OC=O), 1172 (C‐O‐C).…”

“…Yield: 0.075 g, 96%; Colourless oil; [α] 20 D = ‐83.3 [ c = 1.0, MeOH, 99% e.e., lit[α] D = ‐97 ( c = 0.34, MeOH)] . IR (NaCl): cm ‐1 2960 (CH 3 ), 2934, 2860 (CH 2 ), 1774 (OC=O), 1171 (C‐O‐C). 1 H NMR (500 MHz, CDCl 3 ): δ= 0.91 (t, J = 7.4 Hz, 3H, ‐CH 2 CH 3 ), 1.12 (d, J = 6.6 Hz, 3H, ‐CH(CH 3 )CH(O‐)C 4 H 9 ), 1.29‐1.44 (m, 3H, ‐CH 2 ‐), 1.45‐1.56 (m, 1H, ‐CH 2 ‐), 1.58‐1.73 (m, 2H, ‐CH 2 ‐), 2.18‐2.26 (m, 2H, ‐OC(=O)CH 2 CH(CH 3 )‐), 2.62‐2.71 (m, 1H, ‐OC(=O)CH 2 CH(CH 3 )‐), 4.01 (ddd, J = 12.0, 8.0, 4.0 Hz, 1H, ‐CH(CH 3 )CH(O‐)C 4 H 9 ).…”

Employment of near infrared spectroscopy to determine oak volatile compounds and ethylphenols in aged red wines

“…Therefore, these compounds could be used as indicators to show that a wine has been aged in the presence of oak wood. cis-Oak lactone was above its perception threshold (0.046 mg/l) (Wilkinson, Elsey, Prager, Tanaka, & Sefton, 2004) in all the wines (Table 1); in the case of the trans isomer, its mean value for all the samples (0.21 mg/l) was inferior to its perception threshold (0.46 mg/l) (Chatonnet, Boidron, & Pons, 1990). These two lactones produce woody and coconut-like aromas in the wine, which add quality.…”

Synthetic Routes to Three Novel Scaffolds for Potential Glycosidase Inhibitors

“…d-Glucose was chosen as the sugar moiety. The 4-hydroxypyridine 56 was allowed to react with 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide under modified Koenigs-Knorr conditions [32] to yield the β-glucopyranoside 58 as the exclusive product. The Oglycosylation (no N-glycosylation was observed) was confirmed at a later stage of the deprotected compound 61: in the HMBC spectrum the anomeric proton 1Ј-H showed a 3 J CH coupling to C-4 of the pyridine.…”