Structure Reassignment and Synthesis of Jenamidines A<sub>1</sub>/A<sub>2</sub>, Synthesis of (+)-NP25302, and Formal Synthesis of SB-311009 Analogues
作者:Jeremy R. Duvall、Fanghui Wu、Barry B. Snider
DOI:10.1021/jo061650+
日期:2006.10.1
and C (8-10). Jenamidines A(1)/A(2) (8) were synthesized from activated proline derivative 43 by conversion to 26 in two steps and 50% overall yield. Acylation of 26 with acid chloride 38d gave 39d, which was deprotected with TFA and then mild base to give 8 in 45% yield from 26. (-)-trans-2,5-Dimethylproline ethyl ester (49) was prepared by the enantioselective Michael reaction of ethyl 2-nitropropionate (51) and methyl vinyl ketone (50) using modified dihydroquinine 60 as the catalyst. Further elaboration converted 49 to natural (+)-NP25302 (12). A Wittig reaction of proline NCA ( 76) with ylide 79 gave 72 as a 9/1 E/Z mixture in 27% yield, completing a one-step formal synthesis of SB-311009 analogues.
Synthesis of a piperidone model compound and revision of the structures of jenamidines A to C
作者:Barry B. Snider、Jeremy R. Duvall、Isabel Sattler、Xueshi Huang
DOI:10.1016/j.tetlet.2004.07.055
日期:2004.8
anhydride (5) provided the unstable product 6, for which the NMR spectral data are quite different from those reported for the ring system of jenamidine A. This suggests that the proposed structures 1 to 3 of jenamidines A to C should be revised to 8 to 10.