Abstract
New routes have been developed for the practical syntheses of dl-Muscone(1) employing cyclopentadecanone(2) as the starting material. In this experiment, addition of bromine to cyclopentadecanone in dried E. Ether solution with a trace of $AlCl_3$ as the catalyst were produced 2-bromocyclopentadecanone(3). This process was enhanced formation of regioselective enolate anion at $C_2$ position. 2-Bromocyclopentadecanone was put into $Li_2CO_3$-LiBr-DMF solution at 140∼150$^{\circ}C$, were produced trans- and cis-2-cyclopentadecen-1-one(4) mixture. Other by-products were reduced by control of reaction temperature and time. Trans- and cis-2-cyclopentadecen-1-one(4) mixture was directly put into dried E. Ether solvent and induce to react dropwise with $CH_3MgBr-Cu_2Cl_2$ complex, all of them got into 1,4-addition, dl-Muscone (1) was formed as the result. Conculsion, through three steps procedure from cyclopentadecanone(2) to dl-Muscone(1), the pure dl-Muscone was obtained with the high proportion of 85%, and synthetic cost was able to be much lower than any other conventional methods as there were no chemical separating steps.
Cyclopentadecanone(2)으로부터 2-cyclopentadecen-1-one(4)까지의 일반적인 합성경로는 여러가지가 있을 수 있다. 본 실험에서는 우선 $C_2$-위치의 선택적인 브롬화반응을 위하여 $AlCl_3$를 써서 엔올산 염화하여 위치선택성을 증가시켰으며, 브롬화 수소 이탈반응에서의 시약 $Li_2CO_3$-LiBr-DMF 조건을 적절히 조절함으로써 화합물(4)를 쉽게 얻을 수 있었다. 이 과정에서 생기는 트랜스형 및 시스형 화합물(4)를 E.Ether 용매속에서 $CH_3MgI-Cu_2Cl_2$ 복합체에 적하하여 반응시킬 경우, 모두 1,4-첨가반응되어 dl-Muscone(1)를 생성함을 결과로 얻었다. 본 실험에서 Cyclopentadecanone(2)으로부터 dl-Muscone(1)까지의 3단계 과정을 통해 순수한 dl-Muscone(1)을 총 85%의 높은 수율로 얻었으며, 별다른 화학적 분리단계를 거치지 않아, 합성단가를 기존의 어느 방법보다 현격히 낮출수 있었다.