Facile synthesis of two diastereomeric indolizidines corresponding to the postulated structure of alkaloid 5,9E- 259B from a Bufonid toad (Melanophryniscus)

• Angela Nelson,
• H. Martin Garraffo,
• Thomas F. Spande,
• John W. Daly and
• Paul J. Stevenson

Beilstein J. Org. Chem. 2008, 4, No. 6, doi:10.1186/1860-5397-4-6

• 5,9E-259B, and b) synthetic 7. Structure shown with relative configuration. Reagents: (i) MeMgI. 96% (ii) PTSA 71%. (iii) TiCl4 CH2Cl2 25 oC 3d 68%. (iv) MsCl, Et3N, THF -40 oC, 74%. (v) Grubbs' catalyst, 25 oC CH2Cl2, 90%. (vi) H2 MeOH Pt/C 79%. (vii) LiAlH4, AlCl3, 73%. (viii) (a) Dess Martin

An efficient synthesis of tetramic acid derivatives with extended conjugation from L-Ascorbic Acid

• Biswajit K. Singh,
• Surendra S. Bisht and
• Rama P. Tripathi

Beilstein J. Org. Chem. 2006, 2, No. 24, doi:10.1186/1860-5397-2-24

• of the hydroxy lactam derivatives 19–22 with pTSA in CH2Cl2 led to the formation of dienyl lactam derivatives 31–34 in good yields (see Table 2). The structures of all the compounds were determined on the basis of spectroscopic data and microanalysis (Supporting Information File 1). Detailed