Applications erythrinane

Scheme 1. Disfavored 5-endo-trig radical cyclization and application to erythrinane framework...

In contrast, the erythrinane synthesis based on the above mentioned cycloadditions of 1,3-butadienes to pyrrole derivatives is fully applicable to that of the ring C-homologue alkaloids. Thus, the phenylhydroindol 100b prepared by [2 - - 2] cycloaddition according to Scheme 13 cyclizes to yield the 2,8-dioxohomoerythrinane 205, which then has been transformed via the 1,7-cyclointermediate 206 to 2,7-dihydrohomoerysotrine (207) (110) (Scheme 37). 

Toda J, Niimura Y, Sano T, Tsuda Y (1998) General Method for Synthesis of Erythrinan and Homoerythrinan Alkaloids (2) Application of Pummerer-iype... 

Westling, M., Smith, R. and Livinghouse, T. 1986. A convergent approach to heterocycle synthesis via silver ion mediated a-ketoimidoyl hahde-arene cychzations. An application to the synthesis of the erythrinane skeleton. J. Org. Chem. 51 1159-1165. 

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