Study On The Oxidative Aromatization Of Dihydro-?-carboline And The Synthesis Of Alkaloids Eudistomins H,I And N

?-Carboline was widely found in nature,due to the diverse biological activities of ?carboline alkaloids,chemical and pharmaceutical researchers have become interested in the synthesis of them.This paper includes the following two parts of work about the synthesis of?-carboline alkaloids.(1)Study on the Oxidative Aromatization of Dihydro-?-carbolinesIn the first part,the oxidative aromatization of 3,4-dihydro-?-carbolines was studied in detail,a method for oxidizing 3,4-dihydro-?-carbolines was developed by using NaClO.This method used DMF as solvent and NaClO as oxidant at 5?.Under this conditions,compounds I-5(a-j)were prepared from corresponding 3,4-dihydro-?carbolines,and yields reched 77%91%.In addition,we also found that NBS and NCS can also efficiently oxidize 3,4-dihydro-?carbolines.?-Carbolines I-5(a-j)were prepared with NBS in 69%-87%yields,and prepared with NCS in 49%-82%yields.(2)Synthesis of ?-carboline alkaloids Eudistomins H,I and N.Using trypamine as starting material and constructing ?-carboline skeleton via BischlerNapieralski reaction,the alkaloids Eudistomin I and Eudistomin H were synthesized in 5 steps and 6 steps in 49%and 43%overall yields respectively.Tryptamine and L-proline were used as the starting materials,3,4-dihydro-?-carboline was prepared via the Bischler-Napieralski reaction from amides.Aafter four steps,the alkaloid Eudistomin N was synthesized in 63%overall yield.