Isoprelaurefucin, new bromo compound from Laurencia nipponica yamada

✍ Scribed by Etsuro Kurosawa; Akio Fukuzawa; Toshi Irie

• Publisher: Elsevier Science
• Year: 1973
• Tongue: French
• Weight: 195 KB
• Volume: 14
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)87131-8

✦ Synopsis

An extensive study of neutral essential oil from Laurencia nipponica Yamada (Rhodomelaceae; Urasozo in Japanese) led to isolation of a new bromo ether in 0.001% yield. It is designated as isoprelaurefucin and assigned structure I on the basis of chemical and spectral evidence and biogenetical point of view described below. Isoprelaurefucin (I), oil, (a), -54.4', Ci5H2002Br2, m/z 394, 392 and 390 (M+), 329, 327 and 325 (M+ -C5H5), 271 and 269 (M+ -C3H6Br). The UV (hmax 224 (s 13,200)~ 'inf 232 (E 9,800), 219 (E 11,800) and 209 nm (E 8,700)) and IR spectrum (urnax 3300, 2130, 1620, 1196, 1178, 1139, 1107, 970 and 876 cm-') showed the presence of conjugated enyne and ether functions. The NMR spectrum displayed signals due to acetylenic proton at 7 7.34 (lH, d, J=2 Hz), two vinyl protons at 7 4.48 (lH, dd, J=16, 2) and 3.85 (lH, dt, J=16, 7) and methyl protons at z 8.92 (3H, t, J=7). In addition, unresolvable six-proton multiplet appeared in the region of 7 6.4-5.2, which are ascribed to protons on carbons bearing bromine and ether oxygen. Isoprelaurefucin is, therefore, shown to be a bicyclic ether having CH3-CH2-g!-, CHIC-CH=CH-and and these were further supported by following observations.