Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5222137 | Tetrahedron | 2009 | 8 Pages |
Abstract
To avoid the epimerization of the C(11a)-stereocenter previously observed in 6,11a-cis-pyrazino[1,2-b]isoquinolin-1,4-diones, we present in this paper the C(3)-alkylation of 1-methoxy-pyrazino[1,2-b]isoquinolin-4-ones to obtain all-cis derivatives through a very reliable protocol. The success of the acid-promoted cyclization to get pentacyclic (R3=arylmethyl) or tetracyclic (R3=2-bromo-2-propenyl) compounds is dependent on the nature of the C(3)-unsaturated chain and of the N-substituent, but these limitations have been overcome by using trifluoromethanesulfonic as a superacid catalyst. The C-(3)-alkylation of pyrazino[1,2-b]isoquinolin-4-one is also studied.
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Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Irene OrtÃn, Juan Francisco González, Elena de la Cuesta, Carmen Avendaño,