664981-82-2Relevant academic research and scientific papers
Isoxazolinyl Spironucleosides: Stereoselectivity of 1,3-Dipolar Cycloadditions of 7-Methylenepyrrolo[1,2-c]pyrimidin-1(5H)-ones
Fischer, Róbert,Hyro?ová, Eva,Drucková, Alexandra,Fi?era, Lubor,Hametner, Christian,Cyrański, Micha? K.
, p. 2364 - 2368 (2007/10/03)
Novel 7-methylenepyrrolo[1,2-c]pyrimidin-1(5H)-ones 11a-c were synthesized from commercially available orotic acid (6). 1,3-Dipolar cycloadditions of mesitonitrile oxide to the exocyclic double bond of the dipolarophiles 11 proceed with complete regioselectivity and lead to the spiroisoxazolinyl nucleosides 13 and 14 in good yields. Attack of the dipole from the less sterically hindered side of the dipolarophile affords C-5/C-7 trans isoxazolines as major isomers predominantly. The protection of the free hydroxyl group by the bulky substituent (TBDPS) leads to formation C-5/C-7 trans isomer 14c exclusively.
