作者:Xiao-Bo Ding、Daniel P. Furkert、Robert J. Capon、Margaret A. Brimble
DOI:10.1021/ol403246j
日期:2014.1.17
A flexible total synthesis of the 2-nitropyrrole-derived marine natural product, (+)-heronapyrrole C, is reported. The approach is based on regioselective access to key building blocks containing the rare 4-substituted 2-nitropyrrole motif. Sharp less asymmetric epoxidation and dihydroxylation and a Shi epoxidation were used to introduce the five stereogenic centers of the bis-THF-diol side chain. The N-benzoyloxymethyl (Boz) protecting group was crucial for functionalization of the 2-nitropyrrole moiety and enabling final deprotection under mild conditions.
Alkylatlon orientation rules in conjugate addition of grignard reagents to nitropyrrole and nitrothiophene systems
Conjugate addition of various Grignardreagents to 1-alkyl-2-nitropyrroles and to 2-nitrothiophene has been investigated. 1-Alkyl-2-nitropyrroles undergo alkylation at 3 and 5 positions with prevalence of the latter isomer. On the contrary, in 2-nitrothiophene system, formation of the 3-isomer prevails. In both systems, a bulkier Grignardreagent favours the 5-isomer formation. This trend can be reversed