Prodigiosin synthesis with electron rich 2,2′-bipyrroles
Why this work is in the frame
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Bibliographic record
Abstract
The prodigiosins possess a linear tripyrrolic scaffold with the A and B pyrrolic rings connected directly in a bipyrrole unit, and the B and C rings joined in a dipyrrin. These red streptomycete metabolites exhibit among other activities, antitumor, antimicrobial, and immunomodulating properties. A new prodigiosin synthesis has been developed that employs electron rich 2,2′-bipyrroles. In particular, undecylprodigiosin and PNU-156804 were synthesized by condensations of 4-methoxy and 4-benzyloxy 2,2′-bipyrroles, 20a and 20b, respectively, with 5-undecylpyrrole-2-carboxaldehyde in 75% and 83% yields. The 4-alkoxy-2,2′-bipyrroles were synthesized from 4-alkoxypyrrolyl butenyl ketones (15a and 15b), which were made by a novel one-pot process from 2-acyl-N-(PhF)pyrrolidin-4-one (13) [PhF = 9-(9-phenylfluorenyl)] using PhFNa in the presence of alkyl halide. A sequence of alkoxy pyrrole 15a and 15b protection, olefin oxidation, Paal–Knorr condensation, and deprotection gave the requisite 4-alkoxy-2,2′-bipyrroles (20). This route offers utility for making 4-alkoxybipyrroles as well as prodigiosins with diversity at the 6-position of the linear tripyrrolic skeleton.Key words: prodigiosin, pyrrole, bipyrrole, PNU-156804, undecylprodigiosin.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it