Peroxyl-Radical Reaction of Retinyl Acetate in Solution

Synthesis of Highly Functionalized Propargylic Alcohols: Direct Addition of Epoxy Acetylides to Aldehydes and Ketones

“…Reaction with the sterically hindered aldehyde b-cyclocitral (8) gave the addition product 9 in 68% yield, whereas the corresponding addition to the b-C 14 -aldehyde 10 [12] furnished the expected adduct 11 with an exceptionally high 97% yield (Scheme 5). The latter is an intermediate in the projected synthesis of a vitamin A metabolite comprising a 2,5-dihydrofuran unit [13]. As expected, epoxypropargylic alcohol 11 cannot be directly obtained by epoxidation of the trienyne 12 (prepared in analogy to the corresponding diol [14]); treatment of the latter with m-chloroperbenzoic acid (mCPBA) provided a complex mixture of several oxiranes and other by-products.…”

“…FAB-MS: Jeol SX102A spectrometer. NMR Spectra: Bruker DRX-400 or DRX-500 spectrometer, in CDCl 3 or C 6 D 6 as solvent and internal standard; abbreviations for 13 C-NMR DEPT spectra: : CH 3 , CH, À : CH 2 , x: C(quart. ).…”

“…3 CH 2 ); 1.41 ± 1.27 (m, 1 H, CH 2 ); 1.35 (s, MeCO); 1.11 ± 1.00 (m, 1 H, CH 2 ); 0.99 (s, t-Bu); 0.14, 0.12 (2s, Me 2 Si). 13 C 6 D 6 ): 89.0 (x, C(1')); 81.7 (x, C(2')); 68.2 (x, C(1)); 64.4 ( , C(3'')); 63.8 (À , CH 2 O); 51.7 (x, C(2'')); 40.1 (À , C(2), C (6) 13 C-NMR (125 MHz, C 6 D 6 ): 89.2 (x, C(1')); 81.5 (x, C(2')); 68.4 (x, C(1)); 64.3 ( , C(3'')); 62.5 (À , CH 2 O); 52.2 (x, C(2'')); 40.0 (À , C(2), C(6)); 25.5, 23.5 (2 À , C(3), C(4), C(5)); 23.4 ( , Me). FAB-MS: 193 (20, [M À OH] ), 73 (100).…”

The Antioxidative Effect of Fullerenes during the Peroxidation of Methyl Linoleate in Toluene

“…The amount of MeL monohydroperoxides (MeLOOH) was determined by reversed-phase HPLC with ultraviolet detection. 10) The amount of fullerenes was determined by reversed-phase HPLC with an Inertsil ODS-80A column (4:6 Â 150 mm; GL Sciences, Tokyo) developed with hexane/ethanol (1:3, v/v) at 1.0 mL/min and detected by the absorbance at 330 nm. -Tocopherol was measured by reversedphase HPLC with fluorescence detection.…”

Reaction of Retinol with Peroxynitrite

“…Compounds 1, 2, 3, 4, 5, and 6 were identified as retinal (3.8%) (4), 13-apo--carotenone (3.6%) (3), 10) 13-cis-14-nitroretinol (3.1%) (1), 13-trans-14-nitroretinol (2.1%) (2), 11,15-epoxyretinol (1.5%) (6), 11,12) and 11,14-epoxyretinol (1.3%) (5), by MS, UV-VIS, 1 H and 13 C NMR data and by comparison with authentic samples (Fig. 2).…”