226717-87-9Relevant academic research and scientific papers
General synthetic pathway to oxygenated 3-methylbenz[g]isoquinoline- 5,10-diones
Krapcho, A. Paul,Waterhouse, David J.
, p. 737 - 750 (2007/10/03)
The synthesis of naturally occurring dioxygenated and trioxygenated 3- methylbenz[g]isoquinoline-5,10-diones has been accomplished. The critical step involved regioselective additions of di- or trifluorobenzylzinc bromides to activated methyl 6-methylnicotinate. Aromatizations of the resultant dihydropyridines followed by hydrolysis led to the corresponding benzylpyridinecarboxylic acids which on annulative-oxidations led to the respective difluoro- or trifluorobenz[g]isoquinoline-5,10-diones. Displacements of fluorides by methoxide led to the di- or trimethoxy analogues which on selective demethylations led to bostrycoidin, 8-O- methylbostrycoidin, tolypocladin, 5-deoxybostrycoidin or 5-deoxy-6-O-methyl- bostrycoidin. The synthesis of isobostrycoidin and isotolypocladin has also been accomplished.
