Traceless Chiral Auxiliaries for the Allene Ether Nazarov Cyclization
摘要:
The key stereochemical factors that determine transfer of asymmetry from the chiral auxiliary to the cyclopentenone in the allene ether version of the Nazarov reaction have been elucidated. On the basis of the new insights into the mechanism, two highly effective chiral auxiliaries were designed and prepared.
Design of Chiral Auxiliaries for the Allene Ether Nazarov Cyclization
摘要:
A 1,3- or a 1,4-cis axial tert-butyldimethylsilyloxy substituent on the pyranose derived chiral auxiliary for the allene ether Nazarov cyclization leads to products in high optical purity. alpha-Pyranose and beta-pyranose derived auxiliaries lead to enantiomeric products.