A Highly Congested Dioxapyrenophane from an Attempted Synthesis of the Highly‐Strained 1,1,6,6‐Tetramethyl[6](2,11)teropyrenophane
Bibliographic record
Abstract
Abstract Synthetic studies aimed at the synthesis of 1,1,6,6‐tetramethyl[6](2,11)teropyrenophane (3 a) led to the synthesis of the structurally unusual dioxa[6.3.3](7,1,3)pyrenophane 29. The strategic approach to access 3 a resembled the one that was successfully applied in the synthesis of the higher homologues 3 b‐e, but had a key difference: three‐atom bridges were utilized instead of two‐atom bridges in the construction of the intermediate pyrenophanes which were slated to serve as precursors to access 3 a. After stepwise approaches to construct the bridges failed, it was found that two ether bridges could be installed easily in the same reaction to afford dioxa[6.3.3](7,1,3)pyrenophane 29. Considerable steric congestion around the dioxa[3.3]metacyclophane substructure arises from the presence of a methyl group on each of the benzylic positions of the three‐atom bridges. Although the conversion of 29 into a [6](2,11)teropyrenophane was unsuccessful, the finding that ether bridges in this structurally uncommon dioxacyclophane could be formed easily offers new opportunities for the synthesis of related cyclophanes that may ultimately serve as viable precursors for the synthesis of [n](2,11)teropyrenophanes.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.002 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".