Synthesis of 2,6-disubstituted dihydropyrans via an efficient BiBr(3)-initiated three component, one-pot cascade.
The rapid synthesis of cis-2,6-disubstituted dihydropyrans is achieved in a three-component, one-pot cascade reaction. BiBr(3)-ediated addition of ketene silyl acetals or silyl enol ethers to beta,gamma-unsaturated cis-4-trimethylsilyl-3-butenal provides a Mukaiyama aldol adduct containing a vinylsilane moiety tethered to a silyl ether. Addition of a second aldehyde initiates a domino sequence involving intermolecular addition followed by an intramolecular silyl-modified Sakurai (ISMS) reaction. Isolated yields of this one-pot reaction vary from 44 to 80% and all compounds were isolated as the cis-diastereomers (10 examples).
Hinkle
Robert J
RJ
Department of Chemistry, the College of William & Mary, P. O. Box 8795, Williamsburg, VA 23187-8795, USA.
Lian
Yajing
Y
Speight
Lee C
LC
Stevenson
Heather E
HE
Sprachman
Melissa M
MM
Katkish
Lauren A
LA
Mattern
M Christa
MC