Abstract
The Diels-Alder adduct (±)-5 of furan to 1-cyanovinyl acetate was converted to (1RS,2RS,6RS,7SR,8SR,10RS)-10-{[(tert-butyl)dimethylsilyl]-oxy}-4-ethoxy (1) and -4-phenyl-3,9,11-trioxa-5-azatetracyclo[5.3.1.02,6.08,10]-undec-4-ene (2). These compounds reacted with TiCl4 to afford stable (1RS,2RS,6RS,7SR,8SR,9SR)-9-{[(tert-butyl)dimethylsilyl]oxy}-9-chloro-4-ethoxy-3,10-dioxa-5-azatricyclo[5.2.1.02,6]decan-8-ol (3) and (1RS,2RS,6RS,7SR,8SR,9SR)-9-{[(tert-butyl)dimethylsilyl]oxy}-9-chloro-4-phenyl-3,10-dioxa-5-azatricyclo[5.2.1.02,6]decan-8-ol (4), respectively.