Aza-Cope Rearrangement—Mannich Cyclizations for the Formation of Complex Tricyclic Amines: Stereocontrolled Total Synthesis of (.+-.)-Gelsemine.

nano-rods zno as an efficient catalyst for the synthesis of chromene phosphonates, direct amidation and formylation of amines

چکیده ندارد.

Stereocontrolled synthesis of angularly substituted 1-azabicyclic rings by cationic 2-aza-cope rearrangements.

A new synthesis of 1-azabicyclic molecules having angular substitution is reported. This method can be employed to prepare a range of 1-azabicylic rings, including ones containing vicinal quaternary carbon centers and three contiguous stereocenters. [structure: see text]

Stereocontrolled total synthesis of (+)-UCS1025A.

Stereocontrolled total synthesis of (+)-vincristine.

An efficient total synthesis of (+)-vincristine has been accomplished through a stereoselective coupling of demethylvindoline and the eleven-membered carbomethoxyverbanamine presursor. Demethylvindoline was prepared by oxidation of 17-hydroxy-11-methoxytabersonine, followed by regioselective acetylation with mixed anhydride method. Although an initial attempt of coupling by using demethylvindol...

Stereocontrolled Total Synthesis of (−)‐Stemaphylline

Homologation of readily available α-boryl pyrrolidines with metal carbenoids is especially challenging even when good leaving groups (Cl- ) are employed. By performing a solvent switch from Et2 O to CHCl3 , efficient 1,2-metalate rearrangement of the intermediate boronate occurs with both halide and ester leaving groups. The methodology was used in the total synthesis of the Stemona alkaloid (-...