本論文旨在研究掩飾鄰苯醌與Oxone及mCPBA的氧化反應,並以一新穎氧化重排反應,得到5,5雙取代-2(5H)-呋喃酮。主要探討掩飾鄰苯醌與兩種氧化試劑之反應類型 : 經由Baeyer-Villiger反應後重排之反應與環氧化反應(epoxidation),並討論其反應機構。取代基效應與溶劑的酸鹼度決定了掩飾鄰苯醌與兩種氧化試劑氧化類型與反應途徑。兩種氧化試劑針對R1,R2雙取代掩飾鄰苯醌均生成環氧化合物;而R2單取代掩飾鄰苯醌則在Oxone氧化與mCPBA(添加NaHCO3)氧化下生成5,5雙取代-2(5H)-呋喃酮。溶劑效應只對於單取代掩飾鄰苯醌於mCPBA氧化下有較大影響,在添加NaHCO3時,生成5,5雙取代-2(5H)-呋喃酮化合物;若不加入 NaHCO3,則得到還氧化產物。最後,利用R2置換為掌性輔助基合成具非鏡像選擇性的5,5雙取代-2(5H)-呋喃酮。
This research is concerned with the studies of oxidation reactions of mask o-benzoquinones using Oxone or mCPBA as oxidants. The oxidation of MOBs could afford epoxidation products or novel rearrangement products via initial Baeyer-Villiger oxidation to form a highly functionalized 5,5-disubstituted 2(5H)-furanones depending on the substituents on MOBs and the reaction condition in the presence or absence of NaHCO3. Oxidation of MOBs in a neutral to acidic condition would give epoxidation of MOB at C4,C5-position, whereas the presence of NaHCO3 during oxidation lead to a Baeyer-Villiger oxidation at the carbonyl position followed by sequential ring cleavage and lactone formation to furnish 2(5H)-furanones. In this research we also have investigated the effect of installing chiral auxiliary on MOB to induce diastereoselectivity during the newly found tandem oxidation-rearrangement reaction of MOBs.