Efficient and Chemoselective Access to 3-(Chloromethyl)coumarins via Direct Cyclisation of Unprotected Baylis-Hillman Adducts

Abstract

Reaction of substituted 2-hydroxybenzaldehydes with t-butyl acrylate in the presence of DABCO has been shown to afford isolable Baylis-Hillman adducts, acid-catalysed cyclisation of which affords the corresponding 3-(chloromethyl)coumarins directly and in high yield.

Key words

heterocycles - synthesis - coumarins - 2H-1-benzopyran-2-ones - Baylis-Hillman reaction

References

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6

Kaye, P. T.; Musa, M. A. Synth. Commun., in press.

8

In our own studies unprotected Baylis-Hillman adducts of this type have only been isolated as minor products in reactions of protected substrates.

14

Nominal m/z values from HRMS analysis.