Chemical Transformation of (+)-Dehydroabietic Acid Leading to a Formal Synthesis of (+)-Coleon A.
作者:Sachihiko IMAI、Hiromitsu TERAO、Takashi MATSUMOTO
DOI:10.1248/cpb.39.3041
日期:——
(R)-6-Hydroxy-7-isopropyl-3-(3-methoxypropyl)-3, 4-dimethylnaphtho[2, 3-b]furan-2(3H)-one (3), prepared from (+)-dehydroabietic acid (2), was converted into (R)-9-acetoxy-6-benzoyloxy-7-isopropyl-3-(3-methoxypropyl)-3, 4-dimethylnaphtho[2, 3-b]furan-2, 5, 8(3H)-trione (10) and its 9-acetyl compound (11) by a series of reactions : sodium borohydride reduction, acetylation, alkaline hydrolysis, benzoyl peroxide oxidation, Jones oxidation, and m-chloroperbenzoic acid oxidation. The trione 10 was further transformed into (R)-5, 6, 8, 9-tetraacetoxy-7-isopropyl-3-(3-methoxypropyl)-3, 4-dimethylnaphtho[2, 3-b]furan-2(3H)-one (15) by alkaline hydrolysis and reductive acetylation. Since the conversion of 15 into coleon A (1) has already been reported, the present work can be regarded as a new formal synthesis of coleon A.
(R)-6-羟基-7-异丙基-3-(
3-甲氧基丙基)-3, 4-
二甲基萘[2, 3-b]
呋喃-2(3H)-酮(3),由(+)-制备
脱氢松香酸(2),转化为(R)-9-乙酰氧基-6-苯甲酰氧基-7-异丙基-3-(
3-甲氧基丙基)-3, 4-
二甲基萘并[2, 3-b]
呋喃-2, 5 ,8(3H)-三酮(10)及其
9-乙酰基化合物(11)经一系列反应:
硼氢化钠还原、乙酰化、碱解、
过氧化苯甲酰氧化、琼斯氧化、间
氯过
苯甲酸氧化。三酮10进一步转化为(R)-5,6,8,9-四乙酰氧基-7-异丙基-3-(
3-甲氧基丙基)-3,4-
二甲基萘并[2,3-b]
呋喃-2(3H) )-酮(15)经碱性
水解和还原乙酰化得到。由于 15 转化为 Coleon A (1) 的过程已经有报道,因此本工作可以被视为 Colon A 的新的正式合成。