cis-2,3-Diphenyl-6,7-dihydro-5H-cyclopenta[b]pyrazine-5,7-dimethanol, prepared by Diels–Alder reaction from cyclopentadiene and appropriately protected 2-imidazolone—followed by dihydroxylation, glycol protection, diamine deprotection, condensation with benzyl, glycol deprotection, oxidative cleavage and reduction—, was used to synthesize (±)-cis-[7-(6-chloro-9H-purin-9-yl)methyl]-2,3-diphenyl-6,7-dihydro-5H-cyclopenta[b]pyrazin-5-yl}methanol, a key intermediate for novel 1′-homocarbanucleosides based on a cyclopenta[b]pyrazine scaffold as shown by its conversion into several 6-substituted purinyl derivatives.
顺式-2,3
-二苯基-6,7-二氢-5H-环戊并[b]
吡嗪-5,7-二
甲醇,由
环戊二烯和适当保护的
2-咪唑啉酮通过 Diels-Alder 反应制备,然后经过二羟基化、
乙二醇保护、二胺脱保护、与苄基缩合、
乙二醇脱保护、氧化裂解和还原、通过将(±)-顺式-[7-(6-
氯-9H-
嘌呤-9-基)甲基]-2,3
-二苯基-6,7-二氢-5H-环戊并[b]
吡嗪-5-基}
甲醇转化为几种 6-取代的
嘌呤基衍
生物,合成了基于环戊并[b]
吡嗪支架的新型 1′-同碳核苷的关键中间体。