Enantiomerically pure trans-3,4-disubstituted tetrahydrothiophenes from diastereoselective thiocarbonyl ylide addition to chiral α,β-unsaturated amides

Article abstract of DOI:10.1021/ol9910565

(matrix presented). Asymmetric 1,3-dipolar cycloadditions of a sulfur-containing 1,3-dipole and α,β-unsaturated camphorsultam amides as dipolarophiles are described. The cycloaddition products, trans-3,4-disubstituted tetrahydrothiophenes, were obtained in high diastereomeric ratios (up to 90:10) and in high yields. Chromatographic removal of the minor diastereomer followed by cleavage of the chiral auxiliary furnished either the enantiomerically pure corresponding alcohol or carboxylic acid.