作者:Mitsuhiro Yoshimatsu、Masataka Kawahigashi、Eiji Honda、Tadashi Kataoka
DOI:10.1039/a605542g
日期:——
Diazomethane add to the enyne sulfones 1, 3, 4, 6–11 regio-
and stereo-selectively to give the
4-alkynyl-5-phenylsulfonyl-4,5-dihydro-3H-pyrazoles 12–15
and 17–19, which are converted by MeLi into the
4-alkynyl-1H-pyrazoles 24, 25, 16, 26, 28, 30 in good yields.
4,5-Bis(alkynyl)-1H-pyrazoles 34, 37 are also obtained by the
same procedure.
重氮甲烷与烯炔砜 1、3、4、6-11 发生回归和立体选择性反应,得到 4-炔基-5-苯磺酰基-4,5-二氢-3H-吡唑 12-15 和 17-19,它们在 MeLi 的作用下转化为 4-炔基-1H-吡唑 24、25、16、26、28、30,收率良好。