New Formal Syntheses of Laurencione, a Labile Dihydrofuranone Derivative from the Red Alga Laurencia spectabilis
作者:Norbert De Kimpe、Angelina Georgieva、Marc Boeykens、Ivan Kozekov、Wim Aelterman
DOI:10.1055/s-1996-4335
日期:1996.9
A straightforward formal synthesis of the marine natural products laurencione was developed, utilizing elaboration of 5-acetoxy-3-chloropentan-2-one as the starting compound. The synthetic route consisted of (i) α-sulfenylation, (ii) α-chlorination of the resulting β-oxo sulfide, (iii) Hg2+-catalyzed methanolysis, (iv) methanolysis of the γ-acetoxy-α,α-dimethoxy ketone with subsequent cyclization and (v) acid hydrolysis of the acetal. Alternatively, laurencione was prepared from 1,1-dichloroacetone by a sequence of reactions involving (i) imination, (ii) regiospecific β-hydroxyethylation, (iii) hydrolysis, (iv) base-induced rearrangement of the resulting functionalized tetrahydrofuran and (v) final acid hydrolysis of laurencione methyl ether.
以 5-乙酰氧基-3-氯戊-2-酮为起始化合物,开发了一种海洋天然产物月桂酮的直接正规合成方法。合成路线包括:(i) δ±-亚硫酰化;(ii) δ-氧硫化物的δ±-氯化;(iii) Hg2+ 催化的甲醇分解;(iv) δ-乙酰氧基-δ±,δ-二甲氧基酮的甲醇分解及随后的环化;(v) 缩醛的酸水解。另一种方法是通过一系列反应从 1,1-二氯丙酮制备月桂二酮,这些反应包括:(i) 亚氨基化;(ii) 区域特异性δ-²-羟乙基化;(iii) 水解;(iv) 碱诱导生成的官能化四氢呋喃的重排;(v) 月桂二酮甲醚的最终酸水解。