Syntheses of cyclopentyl nucleoside (_)-neplanocin a through tetrazole-fragmentation from cyanophosphates
Hiroki Yoneyama, Kenji Uemura, Yoshihide Usami, Shinya Harusawa
Index: 10.1016/j.tet.2018.03.020
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Abstract
We recently reported a novel synthetic method for five-membered unsaturated cyclic compounds from ketones involving cyanophosphates (CPs) under neutral conditions, in which alkylidene carbenes generated through tetrazole-fragmentation undergo [1,5]-C_H insertions to produce the target compounds. The present paper describes the use of the tetrazole-fragmentation from CPs for the efficient and practical syntheses of (_)-neplanocin A and a protected tetrol, the latter of which is an important synthetic precursor of both (_)-neplanocin A and its analogues. Furthermore, formation of an unusual dihydropyran derivative was observed during the synthetic study of the tetrol.