Intramolecular Diels-Alder cycloadduct 10 was converted to the Stemona alkaloid stenine (1) via a reaction sequence that features a Curtius rearrangement (12 --> 13), Eschenmoser-Claisen rearrangement (19 --> 20) and stereoselective free radical allylation (4 --> 21).
DOI:
10.1021/jo00313a003
作为产物:
描述:
Lithium; (E)-hexa-3,5-dien-1-olate 、 trans 2,4-pentadienoyl chloride 以98%的产率得到[(3E)-hexa-3,5-dienyl] (2E)-penta-2,4-dienoate
参考文献:
名称:
Total synthesis of (dl)-stenine
摘要:
Intramolecular Diels-Alder cycloadduct 10 was converted to the Stemona alkaloid stenine (1) via a reaction sequence that features a Curtius rearrangement (12 --> 13), Eschenmoser-Claisen rearrangement (19 --> 20) and stereoselective free radical allylation (4 --> 21).
A Diels-Alder approach to Stemona alkaloids: total synthesis of stenine
作者:Cheng Yi Chen、David J. Hart
DOI:10.1021/jo00067a015
日期:1993.7
A total synthesis of dl-stenine (4) is described. Key features involve (1) use of an intramolecular Diels-Alder cycloaddition-aminimide rearrangement sequence to construct the perhydroindole substructure (29 --> 36 --> 27), (2) application of an Eschenmoser-Claisen rearrangement-iodolactonization sequence to prepare the butenolide substructure (58 --> 59 --> 61), (3) use of a free-radical allylation to introduce the C(9)-ethyl group (61 --> 62), and (4) thermal cyclization of an amino ester to afford azepinone 68. A variety of intermolecular and intramolecular Diels-Alder reactions, including examples in which alpha,beta-unsaturated thioesters play the role of dienophile, are also described.
CHEN, CHENG-YI;HART, DAVID J., J. ORG. CHEM., 55,(1990) N6, C. 6236-6240