✍ Scribed by Sape S. Kinderman; Robin Doodeman; Jetze W. van Beijma; Jaap C. Russcher; Kim C. M. F. Tjen; T. Martijn Kooistra; Homayun Mohaselzadeh; Jan H. van Maarseveen; Henk Hiemstra; Hans E. Schoemaker; Floris P. J. T. Rutjes
No coin nor oath required. For personal study only.
A variety of allylic O,O-and N,O-acetals were synthesized using a mild palladium-catalyzed coupling of an alcohol or sulfonamide with an alkyl or aryl 1,2-propadienyl ether. The resulting linear acetals were used for the synthesis of unsaturated rings via ring-closing metathesis, in which the acetal carbon ± a precursor for oxycarbenium or N-sulfonyliminium ions, respectively ± served as a reactive center for further introduction of functional groups. The products ± unsaturated oxygen and nitrogen heterocyclic scaffolds ± offer multiple opportunities for derivatization as illustrated with the synthesis of substituted dihydropyrans, chromenes, enantiopure tetrahydropyridines and an enantiomerically pure quinolizidine amino acid.
📜 SIMILAR VOLUMES
## Abstract Ring closing metathesis of acetal‐tethered enynes proceeds smoothly in the presence of ethene and Grubbs II catalyst to give perhydropyran and ‐oxetan derivatives.