ASYMMETRIC DESYMMETRIZATION OF A PSEUDO-MESO ENDO-TRICYCLO[5.2.1.0(2,6)]DECA-4,8-DIEN-3-ONE BY CHIRAL AMINES

A novel route to the enantiopure endo-tricyclodecadienone system has b een realized starting from the readily accessible oxy-endo-tricyclo[5. 2.1.0(2,6)]deca-4,8-dien-3-one 4. Dynamic kinetic resolution of (+/-)- 4 using (S)-prolinol or its methyl ether leads to the corresponding en aminones 6b,c in high yields and with a de of 50%. Complete separation of the diastereomers of 6b is conveniently accomplished via their ace tates. The absolute stereochemistry of the major diastereomer was show n to be ent-6b. Reductive elimination of the chiral auxiliary in ent-6 b with lithium aluminum hydride affords optically pure parent tricyclo decadienone (+)-1 (X=H) in good overall yield. Copyright (C) 1996 Else vier Science Ltd.