Total Syntheses Of Lundurines Alkaloids

Azocinoindole,a featuring unique indole fused with an eight-membered ring,is the common skeleton core of deoxyisoaustamide,oaramine N,grandilodine,lapidilectine B and lundurine A-D.These alkaloids not only present complex structural characteristics,but also exhibit potent anti-tumor and antiflammatory biological activities.Therefore,exploration of the total synthesis of azocinoindole alkaloids,as well as development of efficient methodologies for constructing the tricyclic skeleton,is of extreme value in organic synthesis.In first chapter,the isolation,structural characterization,and biologicals studies as well as total synthesis of lundurines are summarized.The structures of lundurines contain three chiral centers and six rings.The azocinoindoles core is a major challenge in the whole synthesis.Based on a new method to build azocinoindole structure in our recent work,we want to apply it to our total synthesis of lundurines.Starting from the 1,4-cyclohexanedione ethylene glycol,we getting propargyl alcohol ester precursor compound by steps.Then,we obtain propargylamines through the catalytic synthesis of cuprous,and apply gold catalysis reaction we found before to construct eight-membered ring.Due to some problem can’t be solved in our next research,we optimize the route of syntheses.The paper continues to study the total syntheses of lundurine alkaloid based on previous work.The preferred oxidation of 1,4-cyclohexanedione to getting acyclic chain propargylalcohol ester by several steps.And then,constructing propargylamines by cuprous catalysis condition.Next,we accomplished azocinoindole structure construction work by using gold catalyst in high yield.Finally,we synthesize the racemic lundurine A-C.The construction of lundurine D and optically active lundurine series compounds still continue.