Formal [4 + 2] Cycloaddition of Donor−Acceptor Cyclobutanes and Aldehydes: Stereoselective Access to Substituted Tetrahydropyrans
作者:Andrew T. Parsons、Jeffrey S. Johnson
DOI:10.1021/ja906755e
日期:2009.10.14
diastereoselective synthesis of 2,6-cis-disubstituted tetrahydropyrans (THPs) via Lewis acid-catalyzed formal [4 + 2] cycloaddition of donor-acceptor cyclobutanes and aldehydes has been developed. THP products are formed in up to 96% yield and 99:1 diastereoselectivity. Aromatic, cinnamyl, and aliphatic aldehydes are competent dipolarophiles in this system. This methodology was extended to a [[2 + 2] + 2] cycloaddition