Synthesis of Damascones and Related Flavoring Compound : ${\bdta}$-Damascone

다마스콘 및 관련 향료물질의 합성 : 베타다마스콘

The synthesis of $\beta-damascone$ (I), an odoriferous natural product, was investigated from 2,2,6-trimethylcyclohexanone (II); (II) was ethynylated by the action of monoacetylide anion prepared from acetylene and sec-butyllithium at -78${\circ}C$, to give an ethynylcarbinol(III), which was isomerized to an acetylcyclohexene(IV) by refluxing in aqueous oxalic or formic acid. (IV) was treated with sec-butyllithium, the enolate was reacted with freshly dried acetaldehyde, and the resultant $\beta-hydroxyketone$ (V) was dehydrated by TsOH to ${\beta}$-damascone, trans-2,6,6-trimethyl-1-crotonyl-1-cyclohexene(I).

방향을 지니는 천연물인 베타다마스콘(I)을 2,2,6-트리메틸시클로헥산온(II)으로부터 출발하여 합성하였다. 아세틸렌의 THF포화용액을 2차 부틸리튬으로 처리하여 얻은 모노아세틸화 음이온을 -78${\circ}C$에서 (II)와 반응시켜 에틴일하고, 이 때 생긴 에틴일카르비놀(III)을 옥살산 또는 포름산과 함께 끓여서 이성질화시켜 일종의 아세틸시클로헥산(IV)을 얻었다. (IV)를 2차 부틸리튬으로 처리하여 생성되는 엔올화 음이온을 잘 건조시킨 아세트알데히드와 반응시켜서 생성되는 베타히드록시케톤(V)을 파라톨루엔술폰산으로 탈수하여 트란스-2,2,6-트리메틸-1-크로톤일-1시글로 헥센, 즉 다마스콘(I)을 합성하였다.