Geometrically Selective Synthesis of Functionalized β,β-Disubstituted Vinylic Sulfoxides by Cu-Catalyzed Conjugate Addition of Organozinc Reagents to 1-Alkynyl Sulfoxides
functionalities has been developed by employing Cu-catalyzed conjugateaddition of an organozincreagent to chiral 1-alkynyl sulfoxide. Since the reaction proceeds with very high syn-selectivity, both geometric beta,beta-disubstituted vinylic sulfoxides were stereoselectively synthesized by changing the combination of 1-alkynyl sulfoxide and the organozincreagent.
[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.