3-羟基-4-苯基-2-丁酮的合成

分别以(E)-1-苯基-1-丁烯-3-酮和4-苯基-2-丁酮为起始原料合成了3-羟基-4-苯基-2-丁酮。以(E)-1-苯基-1-丁烯-3-酮为起始原料,经过环氧化和还原两步反应得到产物;第1步环氧化反应,用双氧水作氧化剂,产率64%;第2步α,β-环氧酮在Pd/C催化作用下用甲酸还原,得到产物3-羟基-4-苯基-2-丁酮,产率67%;该路线总产率为43%。以4-苯基-2-丁酮为起始原料,经过烯醇硅醚中间体氧化得到产物;4-苯基-2-丁酮在六甲基二硅胺作用下与三甲基碘硅烷反应得到4-苯基-2-丁烯-2-基三甲基硅醚,产率为75%;第2步烯醇硅醚用间氯过氧苯甲酸氧化,得到产物3-羟基-4-苯基-2-丁酮,产率达71%;该路线总产率为53%。以(E)-1-苯基-1-丁烯-3-酮为起始原料的合成路线总产率略低,但操作简单,试剂价廉易得,是更为实用可行的合成路线。

Synthesis of 3-Hydoxy-4-phenyl-2-butanone

3-Hydroxy-4-phenyl-2-butanone has a pleasant mild, warm, creamy and sweet aroma, which is widely used in various flavor formulations. Two different methods of preparing 3-hydroxy-4-phenyl-2-butanone were studied starting from (E)-1-phenyl-1-buten-3-one and 4-phenyl-2-butanone respectively. (E)-1-Phenyl-1-buten-3-one was converted to 3-hydroxy-4-phenyl-2-butanone through epoxidation and reduction. The first step reaction used H2O2 as oxidant to give 1-phenyl-1,2-epoxy-3-butanone in 64% yield; 1-phenyl-1,2-epoxy-3-butanone was reduced by HCOOH at the presence of Pd/C to produce 3-hydroxy-4-phenyl-2-butanone in 67% yield. The overall yield was 43%. 4-Phenyl-2-butanone was converted to 3-hydroxy-4-phenyl-2-butanone through the oxidation of the intermediate silyl enol ether. 4-Phenyl-2-butanone reacted with trimethylsilyl iodide at the presence of hexamethyldisilazane to give 4-phenyl-2-buten-2-yl trimethylsilyl ether in 75% yield. The obtained silyl enol ether was oxidized with m-chloroperoxybenzoic acid to give 3-hydoxy-4-phenyl-2-butanone in 71% yield. The overall yield was 53%. The synthetic route starting from (E)-1-phenyl-1-buten-3-one is one more practical route due to easy operation and commercially available cheap reagents although with a little lower overall yield.