Treatment of denudatine 1 with 10% HCl soln. at 45-50℃ for 3 days leads to a pair of epimers 4A and 4B, Structures of 4A and 4B have been elucidated on the basis of chemical and spectral methods.
The reactions of denudatine 1 and diacetyldenudatine 2 with NBS-50% HOAc soln. afforded 4 and 6, respectively, in high yields.Treatment of 6 with (Ac)_2CO-Pyr. gives 7. The structures of 3,6 and 7 were deduced on the ...The reactions of denudatine 1 and diacetyldenudatine 2 with NBS-50% HOAc soln. afforded 4 and 6, respectively, in high yields.Treatment of 6 with (Ac)_2CO-Pyr. gives 7. The structures of 3,6 and 7 were deduced on the basis of spectral and chemical methods.展开更多
We study the open question on determination of jumps for functions raised by Shi and Hu in 2009. An affirmative answer is given for the case that spline-wavelet series are used to approximate the functions.
文摘Treatment of denudatine 1 with 10% HCl soln. at 45-50℃ for 3 days leads to a pair of epimers 4A and 4B, Structures of 4A and 4B have been elucidated on the basis of chemical and spectral methods.
文摘The reactions of denudatine 1 and diacetyldenudatine 2 with NBS-50% HOAc soln. afforded 4 and 6, respectively, in high yields.Treatment of 6 with (Ac)_2CO-Pyr. gives 7. The structures of 3,6 and 7 were deduced on the basis of spectral and chemical methods.
基金Supported by NSFC(Grant Nos.11071065 and 11171306)
文摘We study the open question on determination of jumps for functions raised by Shi and Hu in 2009. An affirmative answer is given for the case that spline-wavelet series are used to approximate the functions.
