Reaction of 7-oxototara-8,11,13-trien-13-yl acetate (3) with acetic
anhydride-perchloric acid affords the γ-pyrone (8) in addition to the
previously reported acetyl derivative (4). Baeyer–Villiger oxidations of
the ketones (3) or (5) have given starting material or complex mixtures, but
the ε-lactone (9) and the rearranged product (11) were isolated from two
experiments with (3). Oxidation of 13-methoxytotara-8,11,13-triene (2) with
Jones reagent gives the 7-oxo derivative (5) and a low yield of a ring B
opened substituted p-benzoquinone (13). Pathways to (11)
and (13) are proposed.
7-氧代-8,11,13-三烯-13-基乙酸酯(3)与乙酸酐-高氯酸反应,除了生成γ-吡喃酮(8)外,还生成了γ-吡喃酮(9)。
酐-高氯酸反应,除了得到之前报道过的乙酰基衍生物(4)外,还得到了 γ-吡喃酮(8)。
乙酰基衍生物 (4)。贝叶-维利格氧化反应
酮 (3) 或 (5) 的贝叶-维利格氧化反应得到了起始原料或复杂混合物,但
(9)和重排产物(11)是在两次与(3)的实验中分离出来的。
(3)的两次实验中分离出来。用琼斯试剂氧化 13-甲氧基托塔拉-8,11,13-三烯 (2)
琼斯试剂进行氧化,得到 7-氧代衍生物 (5) 和低产率的环 B
开环取代的对苯醌 (13)。提出了 (11)
和 (13) 的途径。