Stereoselective synthesis of (+)-polyoxamic acid based on the synthesis of chiral oxazine.

A concise, stereocontrolled synthesis of (+)-polyoxamic acid was achieved. Starting from trans-oxazoline as a chiral building block, the key step involves diastereoselective oxazine formation catalyzed by palladium(0).

Diastereoselective synthesis of polysubstituted pyrrolidinone as a key intermediate for the anticancer agents by palladium(II)-catalyzed carboxylation.

Palladium(II)-catalyzed carboxylation of chiral olefins 6a-d has been examined under various conditions. In the weak basic condition (K2CO3), 7a-d were obtained in good yields. Alternatively, in the strong basic condition, pyrrolidinones 8a-d were obtained resulting in excellent yields and with high diastereoselectivity.