Reductive Chloro- and Thioallylations: Stereoselective Two-Step Transformations of Esters and Lactones into Functionalized cis- and trans-Vinyloxiranes

✍ Scribed by Christian Hertweck; Wilhelm Boland

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 255 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199810)1998:10<2143::aid-ejoc2143>3.0.co;2-d

✦ Synopsis

A practical and straightforward procedure is described for diastereoselectivities. The β-hydroxy intermediates were stereoselectively converted into the corresponding cis-or the diastereoselective synthesis of functionalized cis-and trans-vinyloxiranes. Readily available esters and lactones trans-vinyloxiranes upon treatment with DBU (for halohydrins) or by alkylation/elimination (for β-hydroxy were sequentially treated in a one-pot procedure with DIBAL-H and (Z)-γ-chloroallyl-BBN or (E)-phenylthio-thioethers). The protocol tolerates several functional groups and promises to be of general applicability. allyltitanium reagents to give syn-β-chlorohydrins or anti-βhydroxy thioethers in good yields with high regio-and