Studies On The Asymmetric Syntheses Of Dibenzopyrans Natural Products And Octanorsimaroubin A

This dissertation aims at the studies on the asymmetric total synthesis of a few naturally occurring dibenzopyrans compounds and triterpenoids nature product Octanorsimaroubin A. It consists of the following four parts:Chapter 1. Directed SN2’substitution of organocopper reagents to allylic electrophiles and application in syntheses (review)The review introduced some representative substrate-directed SN2’substitution of organocopper reagents to allylic electrophiles, and application in natural products syntheses.Chapter 2. Studies on the asymmetric synthesis of dibenzopyrans derivativesThe total syntheses of the non-natural hexahydrocannabinol (HHC) in recent years are reviewed in details. Using (+)-(S)-carvone as starting material, the total synthesis of (+)-Machaeridiol B and (+)-Machaeriol B has been facilely completed via a highly regio-and stereoselective SN2’reaction of arylcyanocuprates to enol silyl ether ofα,β-epoxycyclohexanone.Chapter 3. Synthetic studies toward (-)-△8-trans-TetahydrocannabinolUsing (-)-(R)-carvone as starting material, the total synthesis of (-)-△8-trans-Tetahydrocannabinol has been facilely completed based on the strategy of a highly regio-and stereoselective SN2’reaction of arylcyanocuprates to enol silyl ether ofα,β-epoxycyclohexanone by our group developed.Chapter 4. Synthetic studies toward Octanorsimaroubin A The synthetic studies of Octanorsimaroubin A were introduced briefly.The framework construction of nature product Octanorsimaroubin A has been studied via a Diels-Alder reaction staring from natural product carvone.