66202-36-6Relevant articles and documents
Total synthesis of (±) 2-spirocyclobutano- and (±) 2- spirocyclopentanobisnorpenicillin V
Claes,Janssen,Vanderhaeghe
, p. 521 - 523 (2007/10/20)
The title compounds are analogues of penicillin V in which the two C-2 methyl groups are replaced by a tri- or tetramethylene group. The reaction sequence for the synthesis of the 2-spirocyclobutane analogue consisted in a cycloaddition of azidoacetyl chloride to benzyl (±) 5-spirocyclobutyl-2-thiazoline-4-carboxylate, followed by reduction of the azido function and N-phenoxyacetylation. Base-catalysed epimerization in the 6-position of the resulting (±) 6α-phenoxyacetamide-2-spirocyclobutylpenam3α-carboxylate followed by catalytic debenzylation afforded the (±) 2-spirocyclobutanobisnorpenicilin V. The smae reaction sequence was applied for the synthesis of the 2-spirocyclopentane analogue. The antibacterial activity of both analogues was very similar to that of penicillin V.
