Glucosylation of the cis- and trans-isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol (1a/1b, 2a/2b, 1a or 2a) was performed to prepare the corresponding alkyl β-D-glucopyranosides, mainly to get analytical data of pure enantiomers of the glucosides (3a-6b), required for subsequent investigations of related compounds with biological activity. One of the employed modifications of the Koenigs-Knorr synthesis resulted in achieving 85-95% yields of pure β-anomers 3a/3b, 4a/4b, 3a or 4a of protected intermediates, with several promoters and toluene as solvent, yielding finally the deprotected products 5a/5b, 6a/6b, 5a or 6a as pure β-anomers. To obtain enantiomerically pure β-anomers of the target structure (3a, 4a, 5a and 6a) for unambiguous structure assignment, an enzymic reduction of 2-(4-methoxybenzyl)cyclohexan-1-one by Saccharomyces cerevisiae whole cells was performed to get (1S,2S)- and (1S,2R)-enantiomers (1a and 2a) of 2-(4-methoxybenzyl)cyclohexan-1-ol. The opposite enantiomers of alkyl β-D-glucopyranosides (5b and 6b) were obtained by separation of the diastereoisomeric mixtures 5a/5b and 6a/6b by chiral HPLC. All stereoisomers of the products (3a-6b) were subjected to a detailed 1H NMR and 13C NMR analysis.
对2-(4-
甲氧基苯基)环己基-1-醇(
1a/
1b,
2a/
2b,
1a或
2a)的
cis和
trans异构体进行
葡萄糖基化,制备相应的烷基β-
D-葡萄糖苷,主要是为了获得纯对映体的
葡萄糖苷(
3a-
6b)的分析数据,以便后续研究具有
生物活性的相关化合物。Koenigs-Knorr合成的一种改进方法之一,通过多种
促进剂和
甲苯作为溶剂,得到了保护中间体的纯β-异构体
3a/
3b、
4a/
4b、
3a或
4a,收率为85-95%,最终得到去保护产物的纯β-异构体
5a/
5b、
6a/
6b、
5a或
6a。为了获得目标结构(
3a、
4a、
5a和
6a)的对映纯β-异构体以进行明确的结构指认,使用
Saccharomyces cerevisiae全细胞对2-(4-
甲氧基苯基)环己基-1-酮进行酶促还原,获得了(1
S,2
S)-和(1
S,2
R)-对映体(
1a和
2a)的2-(4-
甲氧基苯基)环己基-1-醇。通过手性高效
液相色谱分离
5a/
5b和
6a/
6b的对映异构体混合物,获得了烷基β-
D-葡萄糖苷的相反对映体(
5b和
6b)。所有产物(
3a-
6b)的立体异构体均经过详细的
1H NMR和
13C NMR分析。