Preparation of Alkyl-Substituted Indoles in the Benzene Portion. Part 12. Enantiospecific Synthesis of Hapalindole O.
作者:Masahiro SAKAGAMI、Hideaki MURATAKE、Mitsutaka NATSUME
DOI:10.1248/cpb.42.1393
日期:——
An important chiral ketone derivative, (3S, 4R)-3-methyl-4-pivaloyloxy-3-vinylcyclohexan-1-one (16) was prepared from (R)-(-)-carvone (10) using a stereo-controlled conjugate addition of the vinyl group to (R)-3-methyl-6-(1-methylethylidene)-4-pivaloyloxy-2-cyclohexen-1-one (13). The first enantiospecific total synthesis of a terrestrial blue-green alga constituent, hapalindole O (1) was accomplished by condensation of this ketone 16 with α, α-dimethyl-1-(p-toluenesulfonyl)-1H-indole-4-methanol (6) to construct the fundamental carbon framework of the hapalindole 21, followed by introduction of the nitrogen function, stereoselective reduction of the tetra-substituted double bond with lithium aluminum hydride, and subsequent isothiocyanate formation.
一种重要的手性酮衍生物(3S, 4R)-3-甲基-4-特戊酰氧基-3-乙烯基环己烷-1-酮(16)由(R)-(-)-香芹酮(10)通过乙烯基基团与(R)-3-甲基-6-(1-甲基乙烯基)-4-特戊酰氧基-2-环己烯-1-酮(13)的立体控制共轭加成制备而成。陆地蓝绿藻成分哈帕林多(hapalindole O)(1)的首次对映选择性全合成是通过将酮16与α,α-二甲基-1-(对甲苯磺酰基)-1H-吲哚-4-甲醇(6)缩合来完成的,以构建哈帕林多(hapalindole)21的基本碳骨架,然后引入氮功能,用锂铝氢化物对四取代双键进行立体选择性还原,并随后形成异硫氰酸酯。