Synthesis of Withasomnines and Their Non-natural Analogues from Aldehydes and 4-Nitro-1-butanol in Three Steps
作者:Deepti Verma、Rahul Kumar、Irishi N. N. Namboothiri
DOI:10.1021/jo400207u
日期:2013.4.5
Total synthesis of all three pyrazole-based withasomnine alkaloids and selected examples of their non-natural analogs has been achieved from readily available aldehydes and 4-nitro-1-butanol in three steps. Since 4-nitro-1-butanol in turn is prepared in two steps via Michael addition of nitromethane to acrylate followed by borane reduction of the ester group and the key 1,3-dipolar cycloaddition step