Synthesis 2007(9): 1385-1391  
DOI: 10.1055/s-2007-965997
PAPER
© Georg Thieme Verlag Stuttgart · New York

Cyclocondensation of (±)-exo,exo-5,6-(Isopropylidenedioxy)-3-(pyrrolidinomethylene)bicyclo[2.2.1]heptan-2-one with N-C-N Dinucleophiles

Isabel Pérez-Castro, Olga Caamaño*, Marcos D. García, Franco Fernández, Carmen López
Departamento de Química Orgánica, Facultade de Farmacia, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
Fax: +34(981)594912; e-Mail: qoolga@usc.es;
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Publikationsverlauf

Received 15 January 2007
Publikationsdatum:
23. März 2007 (online)

Abstract

A number of protected 2-substituted 5,6,7,8-tetrahydro-5,8-methanoquinazoline-6,7-diols were prepared by condensation of amidines with (±)-exo,exo-5,6-(isopropylidenedioxy)-3-(pyrrolidinomethylene)bicyclo[2.2.1]heptan-2-one. Deprotection of the 2-phenyl derivative was followed by its one-pot transformation into a 1:1 mixture of (±)-cis- and (±)-trans-2-phenyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine-5,7-dimethanol by oxidative glycol cleavage and subsequent reduction with sodium borohydride.

25

Anisotropy of the protons of the endocyclic methylene group of the trans-isomer arises from different intramolecular interactions of the hydroxymethylene groups.