10183-74-1Relevant articles and documents
A divergent strategy to the withasomnines
Foster, Robert S.,Huang, Jianhui,Vivat, Jerome F.,Browne, Duncan L.,Harrity, Joseph P. A.
, p. 4052 - 4056 (2009)
A concise synthesis of three members of the withasomnine family of natural products is reported. The synthesis features a regioselective sydnone-alkynylboronate cycloaddition followed by Suzuki cross coupling and silyl group removal, and marks the first d
Radical cyclisation onto pyrazoles: Synthesis of withasomnine
Allin, Steven M.,Barton, William R.S.,Bowman, W.Russell,McInally, Tom
, p. 4191 - 4193 (2002)
A novel synthetic protocol for the synthesis of [1,2-b]-fused bicyclic pyrazoles has been developed using radical cyclisation. The protocol uses cyclisation of pyrazole-1-(ω-alkyl) radicals generated from 1-[ω-(phenylselenyl)alkyl]-pyrazole precursors. The pyrazole natural product, withasomnine (3-phenyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole), and larger ring analogues have been synthesised in good yield using the protocol. A Bu3SnH-mediated oxidative cyclisation mechanism is facilitated by azo or Et3B radical initiators acting as oxidants of the intermediate π-radicals.
5-(Methylthio)tetrazoles as versatile synthons in the stereoselective synthesis of polycyclic pyrazolines via photoinduced intramolecular nitrile imine-alkene 1,3-dipolar cycloaddition
Pla, Daniel,Tan, Derek S.,Gin, David Y.
, p. 2407 - 2415 (2014/05/20)
A key thioether substituent in readily accessible 2-alkyl-5-(methylthio) tetrazoles enables facile photoinduced denitrogenation and intramolecular nitrile imine 1,3-dipolar cycloaddition to afford a wide range of polycyclic pyrazoline products with excellent diastereoselectivity. The methylthio group red-shifts the UV absorbance of the tetrazole, obviating the requirement in all previous substrate systems for at least one aryl substituent, and can subsequently be converted into a variety of other functionalities. This synthetic platform has been applied to the concise total syntheses of the alkaloid natural products (±)-newbouldine and withasomnine. This journal is the Partner Organisations 2014.
Synthesis of withasomnines and their non-natural analogues from aldehydes and 4-nitro-1-butanol in three steps
Verma, Deepti,Kumar, Rahul,Namboothiri, Irishi N. N.
, p. 3482 - 3486 (2013/06/26)
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 t