PMHS-Mediated Couplings of Alkynes or Benzothiazoles with Various Electrophiles: Application to the Synthesis of (−)-Akolactone A
作者:William P. Gallagher、Robert E. Maleczka
DOI:10.1021/jo034463+
日期:2003.8.1
Polymethylhydrosiloxane (PMHS) in combination with CsF facilitates the cross-coupling of alkynes or benzothiazoles with an array of vinyl, styryl, and aryl halides or nonaflates as well as acid chlorides. Experimental and spectroscopic evidence indicates that these reactions involve the in situ generation of a siloxyl intermediate. These cross-couplings proceed relatively quickly at room temperature
The first synthesis of (+)- and (−)-akolactone A is described by using Pd-catalyzed carbonylation. A comparison of the optical rotation of both enantiomers of akolactone A and the natural compound suggests that the absolute configuration at the 4-position of akolactone A is R.
本研究首次利用钯催化羰基化技术合成了(+)-和(-)-阿可内酯 A。通过比较阿可内酯 A 的两种对映体和天然化合物的旋光性,表明阿可内酯 A 的 4 位绝对构型为 R。