Naslov
Stereocontrolled conversion of 1-(3-hydroxyprop-1-enyl)uracil isomers into polyfunctional 3, 9-propane- and 3, 9(9, 3)-propeno-aza-9H-xanthines

Autori
Jokić, Milan ; Škarić, Vinko

Izvornik
Journal of the Chemical Society. Perkin Transactions 1 (1472-7781) (1990), 8; 2225-2232

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
uracil isomers; 3; 9-propane- and 3; 9(9; 3)-propeno-aza-9H-xanthines

Sažetak
With 1, 8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1-(3-azido- (6) and 1-(3-trityloxy-2- methylsulphonyloxypropyl)-3-methyluracil (12) underwent elimination to give the respective E- and Z-prop-1′-enyl isomers. Treatment of (E)- (15) and (Z)- (16) 1-(3-hydroxyprop-1-enyl)-3-methyluracil with Br2-MeOH generated asymmetric centres at C-1′ and C-2′, providing threo- (17) and erythro- (18) 5-bromo-1-(2-bromo-3- hydroxy-1-methoxypropyl)-3-methyluracil. Conversionof compound (17) and (18) into erythro- (19) and threo- (20) 5-bromo-1-(2, 3-epoxy-1-methoxypropyl)-3- methyluracil was accomplished under mild DBU-elimination conditions. The reaction of the diastereoisomeric epoxides (19) and (20) with NaN 3-DMF produced the respective erythro- (21) and threo- (22) 1-(3-azido-2-hydroxy-1-methoxypropyl)-3-methyluracil. These isomers underwent two types of intramolecular cyclisation reaction, which gave trans- (23) and cis- (24) 2-azidomethyl-3-methoxy-6-methyl-2, 3-dihydro-oxazolo[3, 2-c]pyrimidine- 5, 7-dione and cis- (25) and trans- (26) 11-hydroxy-12-methoxy-1-methyl-3, 9- propano-8-aza-9H-xanthine. The elimination reaction of 12-methoxy-1-methyl-11- methylsulphonyloxy-3, 9-propano-8-aza-9H-xanthine (29) by DBU led to formation of 12-methoxy-1-methyl-9, 3-propeno-8-aza-9H-xanthine (30). Its 3, 9-propeno isomer (33) was obtained from a DBU-elimination of 11-bromo-10-methoxy-1-methyl-3, 9- propano-8-aza-9H-xanthine (32). The 9, 3-propeno compound (30) was also converted into 11-bromo-10, 12-dimethoxy-1-methyl-3, 9-propano-8-aza-9H-xanthine (34) on treatment with Br2-MeOH.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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