Natural products as templates for bioactive compound libraries: part 2. Novel modifications of vasicine (peganine) core via efficient and regioselective generation of 3-lithiodeoxyvasicine and its stereoselective addition to aliphatic ketones section sign.

A general procedure for direct lithiation of deoxyvasicine was developed. 3-Lithiodeoxyvasicine intermediate was found to react with various aliphatic ketones providing derivatives of 3-(hydroxyalkyl)deoxyvasicine in good yields. Similar reaction with 4-alkylcyclohexanones yielded respective trans-adducts exclusively. This novel protocol was successfully scaled-up to result in multigram quantities of vasicine-containing core building blocks suitable for production of compound libraries. The described synthetic methodology offers access to a wide range of compounds with potentially beneficial biological profiles.

Natural products as templates for bioactive compound libraries: synthesis of biaryl derivatives of (+/-)-vasicine.

A reliable and high-yielding procedure for preparation of 7-aryl and 7-heteroaryl derivatives of (+/-)-vasicine in two steps from the naturally occurring material is described. This protocol broadens the chemical space for selective modifications of the vasicine tricyclic structure, thereby making it a valuable starting point for the development of novel compound libraries with potentially beneficial biological profiles.