Camphor‐Derived <i>N</i>‐Acryloyl and <i>N</i>‐Crotonoyl Sultams: Practical Activated Dienophiles in Asymmetric <i>Diels‐alder</i> Reactions. Preliminary Communication

Abstract

Abstract Starting from (+)‐camphor‐10‐sulfonyl chloride ( 5 ), the crystalline sultam 8 was easily prepared. Lewis ‐acid‐promoted Diels‐Alder additions of the crystalline N ‐acry‐loyl and N ‐crotonoyl derivatives 9 and 10 , respectively, to cyclopentadiene and 1,3‐butadiene at −130 to −78° furnished adducts 11 , 12 and 17 with high chiral efficiency. Crystallization of the adducts and nondestructive removal of 8 gave either alcohols 13 , 14 and 18 ir acid 19 in 99% enantiomeric purity. The sense of induction was reversed on using the enantiomer of 8 as the auxiliary. The structure of 10 was established by X‐ray diffraction analysis.