Highly diastereoselective diels-alder reaction of optically active 2-p-tolylsulphinyl-2-cycloalkenones with cyclopentadiene

✍ Scribed by I. Alonso; J.C. Carretero; J.L. Garcia Ruano

• Book ID: 104233118
• Publisher: Elsevier Science
• Year: 1989
• Tongue: French
• Weight: 224 KB
• Volume: 30
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)80676-6

✦ Synopsis

The Diels-Alder reaction of (S)-Z-ptolylsulphinyl-2-cyclopentenone (and 2cyclohexcnone) with cyclopentadiene, catalized by AlCl3 and AlEtClz, occurs at room temperature with complete facial diastereoselectivity, but with moderate endo-exe selectivity.

Substituted enantiomerically pure o,Bunsaturated sulphoxides have currently received considerable attention as chiral dienophilesl and chiral Michael acceptors as welie Especially, the cycloalkenone sulphoxides 1 and 2, reported by Posner,3 have been widely used in asymmetric Michael additions and nicely applied to the enantioselective synthesis of several natural products.* Nevertheless, there is no example, to the best of our knowledge, in which 1 or 2 are used in asymmetric Diels-Alder reactions. We hereby report the highly diastereoselective catalyzed cycloaddition of cyclopentadiene to cycloalkenones 1 and 2.