Optically active synthons containing tetra- and dihydropyrimidine rings
作者:Alexander L. Weis、Felix Frolow、Rosita Vishkautsan
DOI:10.1002/jhet.5570230313
日期:1986.5
Opticallyactive condensed derivatives of hydroxytetrahydropyrimidines and dihydropyrimidines were prepared by condensation of (+)pulegone with amidines and guanidine. The structure, the possible mechanism of formation of these compounds, and the existence of amidinic tautomerism are discussed on the basis of the measured spectral data and x-ray diffraction analysis.
Biginelli-Atwal condensations of (+)-pulegone with (thio)ureas and guanidine afford hexahydroquinazoline-2(1H)-ones (-thiones) and/or 2-amino-1,3-thiazines with selectivities that depend on both the (thio)ureas and the experimental conditions. Carboannelation of these heterocyclic adducts with diethyl ethoxymethylenemalonate leads to uncommon pyrimidoquinazoline and pyrimidobenzothiazine systems.