(-)- and (+)-Syringolide 1 have been synthesized from 2,3-O-isopropylidene-beta-threo-pentulofuranose (1), which was readily prepared from D- or L-xylose, respectively. Condensation of 1 with 3-oxooctanoic acid and treatment of the ester with TFA:H2O (9:1) produced syringolide 1 in 6.3% yield for the two steps. According to the same synthetic route by replacing 3-oxooctanoic acid with 3-oxo-7-octenoic acid, (-)-Delta(7)-syringolide 1 was prepared in 5.8% yield. Primary P-keto esters of arabinulose and fructose were also prepared to test the selectivity of the biomimetic cyclization to form syringolide analogs.
(-)-和(+)-
松柏醇内酯1已从2,3-O-异丙叉基-β-赤-五碳糖醛酸(1)中合成,而1则分别由D-或
L-木糖简便制得。1与3-氧基
辛酸进行缩合,随后将酯与TFA:
H2O(9:1)处理,得到
松柏醇内酯1,两步收率为6.3%。按照相同的合成路线,用3-氧基-
7-辛烯酸替代3-氧基
辛酸,得到了(-)-Δ(7)-
松柏醇内酯1,收率为5.8%。还制备了
阿拉伯糖和
果糖的初级P-
酮酸酯,以测试
生物模拟环化反应生成
松柏醇内酯类似物的选择性。