Stereocontrolled Synthesis of 1,3‐Substituted 2‐Oxabicyclo[3.1.0]hexanes as Ring‐Constrained Tetrahydrofuranosyl C‐Glycosides
Bibliographic record
Abstract
Abstract Herein, we describe the stereocontrolled synthesis of 2,3‐α‐methano 2‐substituted‐5‐( S )‐hydroxymethyl tetrahydrofurans, (formally 1,3‐disubstituted 2‐oxabicyclo[3.1.0]hexanes), using a TFA‐mediated destannylative cyclopropanation reaction, starting from commercially available 4‐( S )‐hydroxymethyl‐butyrolactone. A variety of chiral aryl, alkynyl and heterocyclic anomeric substituents were prepared in good to excellent yields. Facile derivatizations of these versatile compounds provide a series of anomerically functionalized chiral non‐racemic 2,3‐α‐methano tetrahydrofurans as potential substrates for heteroatom mediated ring opening reactions of potential interest in medicinal chemistry. Acid‐promoted methanolysis of a phenyl C‐glycoside analogue resulted in cleavage of the cyclopropane ring and formation of (1 S ,4 S ,6 R )‐6‐methyl‐1‐phenyl‐2,7‐dioxabicyclo[2.2.1]heptane, a novel dioxabicyclo ketal and its oxocarbenium ion mediated oligomers.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 0.001 |
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".