USE OF BETA-PHENYLSULFINYL-ALPHA,BETA-UNSATURATED CARBONYL DIENOPHILES IN DIELS-ALDER REACTIONS

The use of β-phenylsulfinyl-α,β-unsaturated carbonyl dienophiles as synthetic equivalents of α,β-ethynyl carbonyl systems has been demonstrated. The sulfoxides were prepared by oxidation of the sulfides, which in turn were obtained from the β-dicarbonyl systems by standard methods. A key feature of the scheme is that the phenylsulfinyl group does not compete with the carbonyl function in determining the regiochemistry of cycloaddition with the highly nucleophilic trans-l-methoxy-3-trimethylsilyIoxy-1,3-butadiene. Application of the methodology to the synthesis of the disodium prephenate dimethyl ace-tals is described. © 1979, American Chemical Society. All rights reserved.