A Facile Synthesis of Lentiginosine Analogues Based on a Highly Regio- and Diastereoselective Allylic Amination Using Chlorosulfonyl Isocyanate

作者：Kim In Su; Li Qing Ri; Dong Guang Ri; Kim Yoo Chang; Hong Yeon Ju; Lee Momi; Chi Ki Whan; Oh Joa Sub; Jung Young Hoon^*

来源：European Journal of Organic Chemistry, 2010, (8): 1569-1573.

DOI：10.1002/ejoc.200901443

• Azasugars
• Synthetic methods
• Inhibitors
• Amination
• Alkaloids

The concise synthesis of the lentiginosine analogues pyrrolizidine alkaloid 2 and pyrroloazepine alkaloid 3 has been achieved from inexpensive and readily available D-lyxose. The key steps in the synthesis included regio- and diastereoselective amination, inter- or intramolecular olefin metathesis, and Appel cyclization. The anti-3,4-amino alcohol 6, essential for the preparation of the title compounds 2 and 3, was synthesized by the regio- and diastereoselective amination of anti-3,4-tribenzyl ether 7 using chlorosulfonyl isocyanate. The reaction of 7 with chlorosulfonyl isocyanate in toluene at 0 degrees C afforded 6 exclusively with a diastereoselectivity of 26:1 in 84 % yield. These results can be explained by the neighboring-group effect, which leads to retention of the stereochemistry.

• 出版日期2010-3