with 1-alkynyl sulfoxide as a sulfinyl source was developed. Bis-sulfinyl alkenes were formed in good yields on treatment of 1-alkynyl sulfoxides with Et(2)Zn in the presence of a Pd-catalyst, wherein zinc sulfenate (or sulfinylzinc) species would be generated in situ to undergo highly syn-selective conjugate addition to the 1-alkynyl sulfoxides. By using 3,3-dimethyl-1-butynyl sulfoxides, formation of
[2,3]-Sigmatropic Rearrangements of 3-Sulfinyl Dihydropyrans: Application to the Syntheses of the Cores of <i>ent</i>-Dysiherbaine and Deoxymalayamicin A
作者:Roberto Fernández de la Pradilla、Nadia Lwoff、Miguel Ángel del Águila、Mariola Tortosa、Alma Viso
DOI:10.1021/jo8015709
日期:2008.11.21
The [2,3]-sigmatropic rearrangement of a variety of configurationally stable diastereomeric allylic sulfinyl dihydropyrans, produced by base-promoted cyclization of sulfinyl dienols, has been studied. In some cases, the efficient transformation of these substrates into dihydropyranols required an in-depth study of reaction conditions, with the preferred protocol relying on the use of DABCO in warm toluene. This methodology has been applied to the syntheses of the cores of ent-dysiherbaine and deoxymalayamicin A by means of efficient tethered aminohydroxylations.