Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Vietnam.
Institute of Chemical Technology, Vietnam Academy of Science and Technology, 1A, TL29, District 12, Ho Chi Minh City 70000, Vietnam.
J Agric Food Chem. 2021 Jun 2;69(21):5882-5886. doi: 10.1021/acs.jafc.1c01875. Epub 2021 May 24.
The diastereoselectivity of adducts in the addition reaction via the Felkin-Anh model is affected 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 ≈ 2:1, while the reduction in structurally related ketones using LiAlH afforded ratios of ≈ 1:1. The experimental data showed no effect of alkyl chain length on either side on the stereoselectivity of adducts. All synthesized analogues were evaluated for attractiveness to weevils in the field. Five novel derivatives, including two alcohols and three ketones, were found to attract weevils in the field trials. Among them, 3-methyldecan-4-one () and 4-methyldecan-5-ol () were found to be the most attractive to the insects.
通过费歇尔-昂恩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著影响。然而，对于非对映选择性，还没有研究过空间位阻烷基链长度的影响。在这项工作中，我们提出了一种使用费歇尔-昂恩模型的β-甲基醇外消旋合成的新策略，以获得各种非对映体比例。烷基格氏试剂与α-甲基醛加成得到的非对映体比例约为 2:1，而结构相关的酮用 LiAlH 还原得到的比例约为 1:1。实验数据表明，烷基链长度对加成物的立体选择性没有影响。所有合成的类似物都在野外对象鼻虫进行了吸引力评估。在田间试验中，发现了五种新型衍生物，包括两种醇和三种酮，它们对象鼻虫具有吸引力。其中，3-甲基癸烷-4-酮（）和 4-甲基癸烷-5-醇（）对昆虫最具吸引力。
