Selective carbon-carbon bond formation at the oxazole ring. Cycloadditions and Michael-type additions of ketenes to 1, 3-oxazoles

…, M Fogagnolo, A Mastellari, A Medici…

Index: Dondoni, Alessandro; Fantin, Giancarlo; Fogagnolo, Marco; Mastellari, Annarosa; Medici, Alessandro; Pedrini, Paola Journal of Organic Chemistry, 1984 , vol. 49, # 19 p. 3478 - 3483

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Citation Number: 11

Abstract

2-(N-Benzyl-N-methylamino)-l, 3-oxazole (IC) and tert-butylcyanoketene (TBCK) give the 5- acyl derivative 4c and a mixture of the diastereomeric 2: l cycloadducta 5 and 6 constituted by a &lactone ring condensed across the former C4-Cs bond of IC. The 4-methyl derivative Id affords the ketone 4d and the enol ester 7, whereas the 4, 5-dimethyl derivative le undergoes the addition of 2 mol of TBCK and ring fission producing a 2, 5-di-hydrofuran ...