An efficient approach to dispacamide A and its derivatives?

Organic & Biomolecular Chemistry Pub Date: 2011-10-06 DOI: 10.1039/C1OB06161E

Abstract

Dispacamide A and new analogs of this marine alkaloid were prepared in seven steps with an overall yield ranging from 12 to 33%. The key step of the strategy was a stereocontrolled Knoevenagel condensation under microwave dielectric heating in the last step. In this condensation, the 2-aminoimidazolin-4-one hydrochloride partners 10a–c were synthesized in three steps with good overall yields (33–79%) via the ring closure of N-guanidino acetic acids 9a–c and the aldehydes 5a,b as the two others building-blocks, in 3 steps with 60–66% overall yields. The six synthetic products have been obtained with a Z geometry about their exocyclic bond on the basis of 13C/1H long-range coupling constants using a gHSQMBC experiment.

Graphical abstract: An efficient approach to dispacamide A and its derivatives
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