Protonation studies on epimeric homoallylic adamantylideneadamantyl alcohols, 4-methyleneadamantylideneadamantane, adamantylideneadamantane (AdAd) and sesquihomoadamantene, and reaction of AdAd and sesquihomoadamantene with NO2+BF4– and PhI(OH)OTs: a stable-ion NMR and theoretical (GIAO-NMR) studyElectronic supplementary information (ESI) available: representative 1D-NMR spectra and tables of cartesian coordinates. See http://www.rsc.org/suppdata/p2/b2/b201660e/
Bibliographic record
Abstract
Under stable-ion conditions, the “pseudo-axial” homoallylic alcohol 1-ax is protonated at the AdAd double-bond and the resulting carbocation undergoes rapid cyclization to produce the oxonium ion 9H+ as the only observable species, which on quenching furnishes the cyclic ether 9. In contrast, protonation of the “pseudo-equatorial” homoallylic alcohol 1-eq gave a persistent homoallylic cation 1a+. Protonation of the methylene-substituted derivative 8 gave a 5 ∶ 1 mixture of two carbocations, in which the minor ion is homoallylic 8aH+. Adamantylideneadamantane AdAd 5 reacts with FSO3H–CH2Cl2 to give the previously observed 5H+ (as a rapidly equilibrating pair of carbocations), together with the oxonium ion 6H+. The outcome of the reaction of AdAd with NO2BF4, NOBF4 and with PhI(OH)OTs is the same, in all cases producing the spirocyclic ketone 6. Sesquihomoadamantene 7 is protonated in FSO3H–SO2ClF and the initially formed carbocation (not observed) rapidly rearranges to 5H+. Compound 7 also reacts with NO2BF4, and TFA–CH2Cl2 to produce the spirocyclic ketone 6 and 5, after quenching. With PhI(OH)OTs the recovered material is 7 itself plus PhI. For comparison, the homoallylic carbocations 1a+, 8aH+, their skeletally rearranged allylic cations 1b+, 8cH+, and the oxonium ions 9H+ and 6H+ were studied computationally by GIAO-NMR at the BLYP/6-31G(d)//BLYP/6-31G(d) level.
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How this classification was reachedexpand
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".