Design of Chiral Auxiliaries for the Allene Ether Nazarov Cyclization

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. α-Pyranose and β-pyranose derived auxiliaries lead to enantiomeric products.