352670-75-8Relevant articles and documents
Oxazine- and oxazole-fused derivatives of the alkaloid boldine and their complete structural and spectral assignments by HMQC and HMBC experiments
Sobarzo-Sanchez, Eduardo,Cassels, Bruce K.,Saitz-Barria, Claudio,Jullian, Carolina
, p. 361 - 366 (2001)
The novel heterocycles 1,11-dimethoxy-2-hydroxy-6-rnethyloxazolo[4,5-k]-5,6,6a,7-tetrahydro-4H-dibenzo [de,g]quinoline, 1,12-dimethoxy-2-hydroxy-6-methyl-9-phenyl-10H-oxazin[5,6-k]-5,6,6a,7- tetrahydro-4H-dibenzo[de,g]quinolin-10-one and 1,11-dimethoxy-2-hydroxy-6-methyl-9-phenyloxazolo[4,5-k]-5,6,6a,7-tetrahydro-4H- dibenzo[de,g]quinoline were prepared starting from the alkaloid boldine. The structures were confirmed and the 1H and 13C NMR spectra were completely assigned using a combination of one- and two-dimensional NMR techniques. Copyright
New heterocyclic skeletons derived from the aporphine alkaloid boldine
Sobarzo-Sanchez, Eduardo,Jullian, Carolina,Cassels, Bruce K.,Saitz, Claudio
, p. 3687 - 3693 (2007/10/03)
The abundant aporphine alkaloid (S)-(+)-boldine (1) was selectively nitrosated with sodium nitrite in acetic acid affording 8-nitrosoboldine (2) which was hydrogenated catalytically to give 8-aminoboldine (3). The latter was used as the starting material for annulations with ethyl ortho-formate to afford the corresponding oxazole ("boldine-9,8-oxazole", 4), and with methyl benzoylformate giving the phenyl-oxazinone ("boldine-9,8-phenyloxazinone", 5). This later product was treated with KOH/EtOH at room temperature and converted quickly into the ring-contracted phenyloxazole ("boldine-9,8-phenyloxazole", 6) in moderate yield.
