A versatile stereocontrolled approach to chiral tetrahydrofuran and tetrahydropyran derivatives by use of sequential asymmetric Horner-Wadsworth-Emmons and ring-closure reactions.
An approach to chiral tetrahydrofuran and tetrahydropyran derivatives based on the sequential use of an asymmetric Horner-Wadsworth-Emmons reaction and a cyclization step is presented. The approach is both stereochemically and structurally versatile since three different cyclization methods can be employed starting from the same HWE product: (i) palladium-catalyzed substitution, (ii) hetero-Michael addition, or (iii) epoxide opening. The asymmetric HWE reaction controls the absolute configuration of the ultimate product, whereas the relative configuration is controlled by the combined influence of the geometric selectivity in the HWE reaction and the stereochemistry of the respective cyclization method.
Vares
Lauri
L
Department of Organic Chemistry, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Rein
Tobias
T
D000447:Aldehydes / Q000737:chemistry; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry*; D007202:Indicators and Reagents; D008958:Models, Molecular; D008968:Molecular Conformation; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D005663:Furans; D007202:Indicators and Reagents; D011714:Pyrans