3-巯基环烷酮和3-巯基环烷醇(链长为C5-C7)是通过将硫代乙酸分别添加到各自的2-环烯-1-酮中并随后通过酶介导的水解和用LiAlH 4还原而获得的。通过使用手性固定相的毛细管气相色谱法分离立体异构体。根据1确定其配置1 H NMR数据和酶催化的动力学拆分。气味阈值和气味质量通过毛细管气相色谱/嗅觉法评估。与类似的无环4-巯基-2-链烷酮和4-巯基-2-链烷醇相比,环状多官能硫醇缺乏果香,热带香气。感觉到的气味特性从煮熟,烤制的蔬菜和肉类到洋葱相关的香精不等。3-巯基环烷酮对映异构体的气味阈值主要受其环的大小而不是其构型的影响。对于3-巯基环烷醇,具有硫醇基的立体异构中心的(S)构型和带有羟基的第二不对称中心的相对构型对于低气味阈值很重要。
A chemoenzymatic access to thiol compounds, including ethyl 3-thiobutanoate, 3-thio-p-menthene and 8-thio-p-menthan-2-one, three compounds of interest in flavour and fragrance chemistry presenting various fruity notes, is proposed. It involves an indium(III)-catalysed hydrothioacetylation of renewable precursors followed by an enzymatic solvolysis of the obtained thioesters by lipases in aqueous or organic solvents. (c) 2010 Elsevier Ltd. All rights reserved.