Wang, Pengzhi Chau Nguyen, Khiem Lindsey, Jonathan S. Synthesis of the Ring C Pyrrole of Native Chlorophylls and Bacteriochlorophylls As part of a program to develop practical syntheses of members of the family of (bacterio)­chlorophylls, two routes to 2-iodo-3-methyl-4-(3-methoxy-1,3-dioxopropyl)­pyrrole, a precursor of the universal ring C, have been developed. The β-ketoester of ring C is expected to give rise to ring E upon Knoevenagel condensation and Nazarov cyclization with a ring D constituent as demonstrated in an analogue synthesis. Two viable routes were developed beginning with <i>N</i>-TIPS-pyrrole or with 4-oxo-2-pentene and TosMIC, affording multi-gram-quantities of this ostensibly simple pyrrole. ring D constituent;4- oxo -2-pentene;ring C;2- iodo -3-methyl;Ring C Pyrrole 2019-08-20
    https://acs.figshare.com/articles/journal_contribution/Synthesis_of_the_Ring_C_Pyrrole_of_Native_Chlorophylls_and_Bacteriochlorophylls/9696293
10.1021/acs.joc.9b01650.s001