산촉매하의 monoterpenone과 formaldehyde와의 反應硏究

Abstract

α위치에 알킬기가 치환된 monoterpenone(thujan-3-one, Pinan-3-one, p-menthan-2-one, p -menthan-3-one)을 산촉매하에서 formaldehyde와 반응시켜 hydroxymethyl monoter penone(4β-hydroxymethyl-thujan-3-one (Ⅰ), 2α-hydroxymethyl-pinan-3-one(Ⅱ), 1β-hydroxymethy-p-menthan-2-one (Ⅲ), 1α-hydroxymethy1-p-menthan-2-one(Ⅳ), 4α- hydoxymethy1-p-menthan-3-one(Ⅶ), 4β-hydroxymethyl-p-menthan-3-one(Ⅷ)을 합성했다. 이 반응은 prins반응과 유사한 aldol condensation 이다. 이때의 반응기전은 알칼리촉매하의 반응과 동일함을 알았다. Hydroxymethylation이 일어나는 반응기전은 a-위치에 alkyl기기가 치환된 탄소원자에서 Proton이 탈리하여 먼저 enol 이 regioselective하게 형성되고, formaldehyde는 입체장해가 적은 α-alkyl-substituted ketone에 우선적으로 공격함으로써 hydroxymethylation이 alkyl가 치환된 탄소에서 regioselective 하게 일어났다. 산촉매하에서 monoterpenone과 formaldehyde의 hydroxymethylation은 bicyclic monoterpenone에서는 regio-, stereoselective하게, monocyclic monoterpenone 에서는regioselective 하게 진행된다는 결론을 얻었다.;The synthetic product of hydroxymethyl monoterpenone was afforded by the acid catalyzed reaction between α-alkyl substituted monoterpenone(thujan-3-one, pinan-3-one, p-menthan-2-one, p-menthan-3-one, etc) and formaldehyde. This reactions involve the aldol condensation analogous to the prins reaction. The preferential position of formaldehyde is alkyl substituted α-carbon atom where these enols are regioselectively formed. The hydroxymethylation of monoterpenone was also proved to happen regioselectively in the position of α-alkyl substituted ketone, whose conformation has less steric hindrance. The hydroxymethylation with the bycyclic monoterpenone, whereas regioselectively only with the monocyclic monoterpenone.