Intramolecular Imino Diels−Alder Reaction of a 3-Vinyl Indole: Application to a Total Synthesis of (±)-Eburnamonine
摘要:
The intramolecular [4 + 2] cycloaddition of imine 1 has been examined under a variety of conditions including thermal; catalysis by acid, lithium cation, and Florisil; and the use of 5.0 M lithium perchlorate in diethyl ether. Cycloadduct 2 was transformed into (+/-)-eburnamonine 3 using acid catalysis. Substrate 1 was prepared by coupling indole-3-carboxaldehyde 7 with the activated p-nitrophenyl ester 9. Subsequent methylenation of 10 gave rise to 11, which upon exposure to fluoride ion provided imine 1.
Intramolecular Imino Diels−Alder Reaction of a 3-Vinyl Indole: Application to a Total Synthesis of (±)-Eburnamonine
摘要:
The intramolecular [4 + 2] cycloaddition of imine 1 has been examined under a variety of conditions including thermal; catalysis by acid, lithium cation, and Florisil; and the use of 5.0 M lithium perchlorate in diethyl ether. Cycloadduct 2 was transformed into (+/-)-eburnamonine 3 using acid catalysis. Substrate 1 was prepared by coupling indole-3-carboxaldehyde 7 with the activated p-nitrophenyl ester 9. Subsequent methylenation of 10 gave rise to 11, which upon exposure to fluoride ion provided imine 1.
Intramolecular Imino Diels−Alder Reaction of a 3-Vinyl Indole: Application to a Total Synthesis of (±)-Eburnamonine
作者:Paul A. Grieco、Michael D. Kaufman
DOI:10.1021/jo9909960
日期:1999.10.1
The intramolecular [4 + 2] cycloaddition of imine 1 has been examined under a variety of conditions including thermal; catalysis by acid, lithium cation, and Florisil; and the use of 5.0 M lithium perchlorate in diethyl ether. Cycloadduct 2 was transformed into (+/-)-eburnamonine 3 using acid catalysis. Substrate 1 was prepared by coupling indole-3-carboxaldehyde 7 with the activated p-nitrophenyl ester 9. Subsequent methylenation of 10 gave rise to 11, which upon exposure to fluoride ion provided imine 1.