102. Camphor-Derived N-Acryloyl and N-Crotonoyl Sultams: Practical Activated Dienophiles in Asymmetric Diels-alder Reactions. Preliminary Communication
     Oppolzer, W.; Chapuis, C.; Bernardinelli, G.
     Helv. Chim. Acta 1984, 67, 1397-1401

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.

DOI : 10.1002/hlca.19840670527