Synthetic Studies of α-Tocopherol. II. Synthesis of Trimethyl-benzoquinone
作者:Takehiko Ichikawa、Hiroko Owatari、Tetsuya Kato
DOI:10.1246/bcsj.41.1228
日期:1968.5
Trimethylbenzoquinone (XII), a raw material for the synthesis of trimethylhydroquinone (XIII), was synthesized from trimethylcyclohexenones and trimethylcyclohexene by oxidation. Ethyl α-propionylpropionate (II) prepared from ethyl propionate was condensed with methyl vinyl ketone to yield 4-methyl-4-ethoxycarbonylocta-3,7-dione (IV), which was then dehydrated with beryllium chloride to give 2,3,6
三甲基苯醌 (XII) 是合成三甲基氢醌 (XIII) 的原料,由三甲基环己烯酮和三甲基环己烯通过氧化合成。由丙酸乙酯制备的 α-丙酰丙酸乙酯 (II) 与甲基乙烯基酮缩合得到 4-methyl-4-ethoxycarbonylocta-3,7-dione (IV),然后用氯化铍脱水得到 2,3,6 -trimethyl-6-ethoxycarbonyl-2-cyclohexen-1-one (V)。产物(V)与碱一起加热,得到2,3,6-三甲基-2-环己烯-1-酮(VI)。IV在乙酸和盐酸的混合物中的溶液的回流也产生VI。当 II 与巴豆醛缩合时,一步得到 2,5,6-trimethyl-2-cyclohexen-1-one (VIII)。1,4(或1,5)-二甲基-5-(或4)-甲酰基-1-环己烯(IX),通过巴豆醛与异戊二烯的 Diels-Alder 反应获得,通过水合肼还原得到 1