Synthesis of β-Methyl Alcohols: Influence of Alkyl Chain Length on Diastereoselectivity and New Attractants of <i>Rhynchophorus ferrugineus</i>
作者:Van-Dung Le、Chi-Hien Dang、Cong-Hao Nguyen、Hong-Ung Nguyen、Thanh-Danh Nguyen
DOI:10.1021/acs.jafc.1c01875
日期:2021.6.2
significantly by the steric effect of bulky groups. However, the influence of steric alkyl chain length has not been studied for the diastereoselectivity. In this work, we present a new strategy for the racemic synthesis of β-methyl alcohols to obtain various diastereomer ratios using the Felkin–Anh model. The addition of alkyl Grignard reagents to α-methyl aldehydes afforded diastereomer ratios of threo/erythro
通过 Felkin-Anh 模型的加成反应中加合物的非对映选择性受大体积基团的空间效应显着影响。然而,尚未研究空间烷基链长度对非对映选择性的影响。在这项工作中,我们提出了一种用于β-甲醇外消旋合成的新策略,以使用 Felkin-Anh 模型获得各种非对映异构体比例。将烷基格氏试剂添加到 α-甲基醛中提供了非对映异构体比率为threo/erythro ≈ 2:1,而使用 LiAlH 4减少结构相关的酮提供了threo/erythro比率≈ 1:1。实验数据表明,任一侧的烷基链长度对加合物的立体选择性没有影响。对所有合成的类似物在田间对Rhynchophorus ferrugineus象鼻虫的吸引力进行了评估。在田间试验中发现五种新型衍生物,包括两种醇和三种酮,可以吸引象鼻虫。其中,3-methyldecan-4-one ( 5b ) 和 4-methyldecan-5-ol ( 11a ) 对昆虫的吸引力最大。