7 alpha-Alkylation and 7,7-bis-alkylation of 20-hydroxyecdysone with propargyl bromide in a lithium -ammonia solution and catalytic reductive spirocyclization of 7,7-bis(2-propyn-1-yl)-14-deoxy-Delta(8(14))-20-hydroxyecdysone

摘要

7 alpha-Alkylation and 7,7-bis-alkylation of 20-hydroxyecdysone with propargyl bromide in a lithium ammonia solution resulted in the formation of 7 alpha-(2-propyn-1-yl)- and 7,7-bis(2-propyn-1-yl)-14deoxy-Delta(8(14))-20-hydroxyecdysone in 92% and 75% yield respectively. Upon catalytic hydrogenation (10% Pd-C) of 7,7-bis(2-propyn-1-yl) derivative spirocyclization occurs by geminal 2-propyn-1-ylgroups. (C) 2016 Elsevier Inc. All rights reserved.