Utility of α-Oxoketene Dithioacetals in Organic Synthesis: Synthesis of Some New Spiro Quinazolin-4-(3H)- one Derivatives

A convenient synthesis of a series of substituted 4'-oxo-3',4'-dihydro-(1'H)-spiro[pyran-4,2'-quinazoline]-
3-carbonitrile and 4'-oxo-3',4'-dihydro-(1'H)-spiro[pyran-4,2'-quinazoline]-3-ethylcarboxylate via the reactions of versatile and readily accessible 3-(4-oxo-3,4-dihydroquinazolin-2(1H)-ylidene)pentane-2,4-dione 1 with the appropriate reagents, is described here.