Organic Letters 2006-10-12

Concise assembly of the polycyclic frameworks associated with the hapalindole and fischerindole alkaloids.

Martin G Banwell, Xinghua Ma, Rebecca M Taylor, Anthony C Willis

Index: Org. Lett. 8(21) , 4959-61, (2006)

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Abstract

[reaction: see text] Reaction of N-methylindole (4) with 6,6-dibromobicyclo[3.1.0]hexane (5) in the presence of silver tetrafluoroborate affords conjugate 7 in 67% yield. This product can be readily elaborated to compounds 12b and 13b which embody the polycyclic frameworks associated with members of the hapalindole and fischerindole classes of alkaloids. The chiral-auxiliary-substituted 6,6-dibromobicyclo[3.1.0]hexanes 21 and 22 react with indole to give adducts likely to be useful in the enantioselective total synthesis of the title alkaloids.