Add time:07/14/2019         Source:sciencedirect.com

The total synthesis of (−)-codonopsinine (1) from the readily available (S)-3-chloropropan-1,2-diol is described. The key steps for the preparation of (−)-codonopsinine (1) involve the regioselective and diastereoselective amination of anti-1,2-dibenzyl ether 11 using chlorosulfonyl isocyanate and intramolecular amidomercuration to form the pyrrolidine ring. Notably, the reaction between anti-1,2-dibenzyl ether and chlorosulfonyl isocyanate in toluene at 0 °C produced the corresponding anti-1,2-amino alcohol 12a as a major product with excellent diastereoselectivity (anti:syn = 29:1). This observation can be explained by the neighboring group participation leading to the retention of stereochemistry.

We also recommend Trading Suppliers and Manufacturers of ethyl 3-(chlorosulfonyl)propanoate (cas 103472-25-9). Pls Click Website Link as below: cas 103472-25-9 suppliers