Nucleophilic Addition to 2,3-Disubstituted Butanal Derivatives and Their Application to Natural Product Synthesis
作者:Hidekazu Horie、Hideaki Akaike、Keisuke Kato、Hiroyuki Akita
DOI:10.1248/cpb.58.1411
日期:——
The reaction of 2,3-anti-2-tert-butyldimethylsiloxy-3-substituted butanal derivative [anti-B, (±)-10 and (±)-16] derived from trans-(2,3)-epoxy butanoate (1) with carbon nucleophiles [α-furyl anion, acetate anion, and indium (In)-assisted allyl anion] has been investigated to give selectively the anti-, anti-adduct D. This anti-stereoselection could be explained by the Felkin–Anh transition state model. Thus obtained anti-, anti-adducts (±)-17 and (±)-38 were formally converted to natural products, (±)-asperlin (2) and (±)-olivose (4), respectively. The major anti-, anti-adduct (±)-26 was converted to (±)-digitoxose (3), while the minor anti-, syn-adduct (±)-27 was also converted to (±)-olivose (4). The reaction of (±)-10 with tert-butyl acetate anion gave predominantly afforded the anti-, anti-adduct (±)-23, which was converted to (±)-1,5-dideoxyhexitol (25). Alternately, the reaction of 2,3-syn-2-tert-butyldimethylsiloxy-3-p-methoxyphenoxy butanal derivative [syn-B, (±)-14] derived from trans-(2,3)-epoxy butanoate (1) with carbon nucleophile (In-assisted allyl anion) afforded a ca. 1 : 1 mixture of the syn-, anti-adduct E [(±)-32 or (±)-34] and syn-, syn-adduct F [(±)-33 or (±)-35]. After separation of this mixture, (±)-34 and (±)-35 were separately converted to (±)-oliose (5) and (±)-boivinose (6), respectively.
2,3-抗-2-叔丁基二甲基硅氧基-3-取代的丁醛衍生物[抗-B,(±)-10和(±)-16]衍生自反式-(2,3)-环氧丁酸酯的反应( 1)与碳亲核试剂[α-呋喃基阴离子、乙酸根阴离子和铟(In)辅助的烯丙基阴离子]进行了研究,以选择性地产生反加合物D。这种反立体选择可以通过Felkin- Anh 过渡状态模型。由此获得的抗-、抗加合物(±)-17和(±)-38分别正式转化为天然产物(±)-asperlin(2)和(±)-olivose(4)。主要的抗、抗加合物 (±)-26 转化为 (±)-洋地黄糖 (3),而次要的抗、顺加合物 (±)-27 也转化为 (±)-橄榄糖 (4) )。 (±)-10与乙酸叔丁酯阴离子的反应主要产生反加合物(±)-23,其转化为(±)-1,5-二脱氧己糖醇(25)。或者,由反式-(2,3)-环氧丁酸酯衍生的2,3-syn-2-叔丁基二甲基硅氧基-3-对甲氧基苯氧基丁醛衍生物[syn-B, (±)-14]的反应 (1)与碳亲核试剂(In辅助烯丙基阴离子)提供约。顺式、反式加合物E[(±)-32或(±)-34]和顺式、顺式加合物F[(±)-33或(±)-35]的1:1混合物。分离该混合物后,(±)-34和(±)-35分别转化为(±)-寡糖(5)和(±)-牛维糖(6)。