Lie Ken Jie Marcel S F, Lau Maureen M L, Lam Corey N W
Department of Chemistry, The University of Hong Kong, Hong Kong, SAR, China.
Lipids. 2003 Dec;38(12):1293-7. doi: 10.1007/s11745-003-1192-8.
A methylene-interrupted C18 keto-acetylenic fatty ester (methyl 12-oxo-9-octadecynoate) was obtained from methyl ricinoleate by bromination-dehydrobromination followed by oxidation. Reaction of methyl 12-oxo-9-octadecynoate with bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide furnished methyl 8-[5-hexyl-3-allyl-furan-2-yl]-octanoate (1, 56%) or methyl 8-15-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (2, 55%). Reaction of methyl 12-oxo-11-chloro- or 11-fluoro-9-octadecynoate (prepared from methyl santalbate--methyl 11-E-9-octadecynoate, found in sandalwood, Santalum album, seed oil) with bis(benzonitrile) palladium(II) chloride gave methyl 8-(4-chloro-5-hexyl-furan-2-yl)-octanoate (3, 59%) or methyl 8-(4-fluoro-5-hexyl-furan-2-yl)-octanoate (4, 50%), respectively. And when methyl 12-oxo-11-chloro- or 11-fluoro-9-octadecynoate was treated with a mixture of bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide, the reaction yielded tetrasubstituted C18 furan derivatives, viz., methyl 8-(3-allyl-4-chloro-5-hexyl-furan-2-yl)-octanoate (5, 54%), methyl 8-[4-chloro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (6, 54%), methyl 8-(3-allyl-4-fluoro-5-hexyl-furan-2-yl)-octanoate (7, 10%), and methyl 8-14-fluoro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (8, 10%). The presence of a fluorine atom in the furan derivatives 4, 7, and 8 was readily characterized by the appearance of doublets for carbon nuclei, which were coupled to the fluorine atom in the 13C NMR spectra. All furan fatty derivatives from this work were characterized by NMR spectroscopic and mass spectrometric analyses. The yields of compounds 7 and 8 were very low (10%) despite attempts to improve the procedure by increasing the amounts of the reactants and catalyst.
通过溴化-脱溴化氢反应然后氧化，从蓖麻油酸甲酯中获得了一种亚甲基间断的C18酮炔脂肪酸酯（12-氧代-9-十八碳炔酸甲酯）。12-氧代-9-十八碳炔酸甲酯与双（苄腈）钯（II）氯化物、烯丙基溴或甲基烯丙基溴反应，得到8-[5-己基-3-烯丙基-呋喃-2-基]-辛酸甲酯（1，产率56%）或8-[5-己基-3-（2-甲基烯丙基）-呋喃-2-基]-辛酸甲酯（2，产率55%）。12-氧代-11-氯-或11-氟-9-十八碳炔酸甲酯（由檀香酸甲酯——在檀香木（Santalum album）种子油中发现的11-E-9-十八碳炔酸甲酯制备）与双（苄腈）钯（II）氯化物反应，分别得到8-（4-氯-5-己基-呋喃-2-基）-辛酸甲酯（3，产率59%）或8-（4-氟-5-己基-呋喃-2-基）-辛酸甲酯（4，产率50%）。当12-氧代-11-氯-或11-氟-9-十八碳炔酸甲酯用双（苄腈）钯（II）氯化物、烯丙基溴或甲基烯丙基溴的混合物处理时，反应生成四取代的C18呋喃衍生物，即8-（3-烯丙基-4-氯-5-己基-呋喃-2-基）-辛酸甲酯（5，产率54%）、8-[4-氯-5-己基-3-（2-甲基烯丙基）-呋喃-2-基]-辛酸甲酯（6，产率54%）、8-（3-烯丙基-4-氟-5-己基-呋喃-2-基）-辛酸甲酯（7，产率10%）和8-[4-氟-5-己基-3-（2-甲基烯丙基）-呋喃-2-基]-辛酸甲酯（8，产率10%）。呋喃衍生物4、7和8中氟原子的存在通过13C NMR谱中与氟原子偶合的碳核的双峰出现很容易得到表征。这项工作中所有的呋喃脂肪酸衍生物都通过NMR光谱和质谱分析进行了表征。尽管尝试通过增加反应物和催化剂的量来改进反应过程，但化合物7和8的产率非常低（10%）。
