A New Efficient Route to 2-Substituted Azulenes Based on Sulfonyl Group Directed Lithiation §

…, N Yamanouchi, T Murafuji, K Kurotobi…

Index: Shibasaki, Toshihisa; Ooishi, Takeo; Yamanouchi, Nobuhiko; Murafuji, Toshihiro; Kurotobi, Kei; Sugihara, Yoshikazu Journal of Organic Chemistry, 2008 , vol. 73, # 20 p. 7971 - 7977

Full Text: HTML

Citation Number: 15

Abstract

Directed lithiation of p-tolyl 1-azulenyl sulfone (1) at the 2-position of the azulenyl group was achieved by using lithium 2, 2, 6, 6-tetramethylpiperidide (LTMP). The azulenyllithium thus generated could be efficiently trapped with various electrophiles to form 2-substituted derivatives 2 in moderate to good yields. p-Tolyl 2-trimethylsilyl-1-azulenyl sulfone (2a) was transformed into cyclic sulfone derivative 3a through the directed lithiation in the p-tolyl ...