Pyran annulation: asymmetric synthesis of 2,6-disubstituted-4-methylene tetrahydropyrans.
[reaction: see text] A reaction process for the asymmetric construction of a variety of cis or trans disubstituted pyrans is described. This sequences allows for the asymmetric convergent union of two aldehydes with silyl-stannane reagent 1 in a two-step process: catalytic asymmetric allylation of the first aldehyde using 1 with a BITIP catalyst, followed by reaction of the alcohol so obtained with a second aldehyde and TMSOTf.
Keck
Gary E
GE
Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA. keck@chemistry.utah.edu
Covel
Jonathan A
JA
Schiff
Tobias
T
Yu
Tao
T
D007202:Indicators and Reagents; D011714:Pyrans / Q000737:chemistry*; D013237:Stereoisomerism
D007202:Indicators and Reagents; D011714:Pyrans