Stereoselective Carbon-carbon Bond Forming Reactions Using Chiral Environment Designed from Carbohydrates

探索以下主题以验证呋喃己糖和吡喃己糖作为非对映选择性碳-碳键形成反应的立体控制剂的有效性。（Z）-3-脱氧-3-C-[（羟甲基）亚甲基]-1，2：5，6-二-O-异亚丙基-α-D-呋喃核糖己糖与1，1-二甲氧基环己烷发生原酸酯Claisen重排反应，得到3.3：1的重排产物非对映异构体混合物。与3，3-二甲氧基环己烯的Claisen重排提供单一产物。研究了这些重排产物的氢化物加成和1，4-共轭加成，其中一些加成具有高度立体选择性。2.通过不同的有机铜试剂或丙二酸二甲酯阴离子与螺环结构中的1，2：5，6-二-O-异亚丙基-α-D-呋喃葡萄糖基环相连的环戊烯-2-烯酮进行共轭加成反应，立体选择性地得到了不同的β-官能化环戊酮衍生物 ...更多信息 .此外，（1 S，3R，4 R，5S）-7-（羟甲基）-3，4-（异亚丙基二氧基）-1-[（1 R）-1，2-（异亚丙基二氧基）乙基]-2-氧杂螺[4.4]壬-6-烯与原乙酸三乙酯的热处理得到具有高水平非对映选择性的Claisen重排产物.各种有机铜试剂与α-D-吡喃葡萄糖苷甲基的4-O-巴豆酰基衍生物的1，4-共轭加成反应具有极高的非对映化学诱导作用，得到在C-4碳原子上带有β-乙烯基化（或烷基化）丁酸酯的加合物。6-O-巴豆酰基衍生物与1，4-共轭加成反应，得到β-碳位构型与4-O-巴豆酰基衍生物相反的加成物。从每种加合物中除去碳水化合物模板，得到对映体纯或高度富集形式的β-乙烯基化（或烷基化）丁酸。烷基与上述4-O-巴豆酰基衍生物的共轭加成反应具有高度的立体选择性。D-半乳糖衍生的和D-甘露糖衍生的2-O-，3-O-巴豆酸酯也可作为1，4-共轭加成反应和Diels-Alder反应的良好立体控制剂。少

The following subjects were explored for verification of the effectiveness of hexofuranoses and hexopyranoses as stereocontroller for diastereoselective carbon-carbon bond forming reactions.1. The orthoester Claisen rearrangement of (Z)-3-deoxy-3-C-[(hydroxymethyl)methylene]-1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranose with 1,1-dimethoxycyclohexane provided a 3.3:1 diasteromeric mixture of the rearrangement products. The Claisen rearrangement with 3,3-dimethoxycyclohexene provided a single product. Hydride additions and 1,4-conjugate additions for these rearrangement products were investigated, and some of the additions proceeded highly stereoselectively.2. The conjugate additions of a variety of organocopper reagents or dimethyl malonate anion to a spirocyclic cyclopent-2-enone connecting a 1,2:5,6-di-O-isopropylidene-α-D-glucofuranosyl ring as a constituent of the spirocyclic structure proceeded stereoselectively affording a variety of β-functionalized cyclopentanone derivatives … More . In addition, the thermal treatment of (1S,3R,4R,5S)-7-(hydroxymethyl)-3,4-(isopropylidenedioxy)1-[(1R)-1.2-(isopropylidenedioxy)ethyl]-2-oxaspiro[4.4]non-6-ene with triethyl orthoacetate afforded the Claisen rearrangement product with a high level of diastereoselectivity.3. The 1,4-conjugate additions of a variety of organocopper reagents to some 4-O-crotonyl derivatives of methyl α-D-glucopyranoside proceeded with exceptionally high levels of diastereochemical induction to provide the adducts carrying a β-vinylated (or alkylated) butanoic ester at the C-4 carbon atom. The 1,4-conjugate additions to a 6-O-crotonyl derivative aforded the adduct incorporating reverse configuration at the β-carbon to that obtained from the 4-O-crotonyl derivatives. Removal of the carbohydrate template from each adduct provided β-vinylated (or alkylated) butanoic acid in enantiopure or highly-enriched form. The conjugate addition of alkyl radicals to the above mentioned 4-O-crotonyl derivative proceeded with high stereoselectivity. The D-galactose-derived and D-mannose-derived 2-O-, 3-O-crotonyl esters also served as good stereocontrollers for 1,4-conjugate addition reactions and Diels-Alder reactions. Less