Highly Regio- and Diastereoselective Synthesis of CF₃‑Substituted Lactones <i>via</i> Photoredox-Catalyzed Carbolactonization of Alkenoic Acids

Trifluoromethylative lactonization of both terminal and internal alkenoic acids by photoredox catalysis has been developed. The use of a Ru photocatalyst and Umemoto’s reagent as a CF₃ source is key in the present carbolactonization. This is the first example of a highly <i>endo</i>- and diastereoselective synthesis of CF₃-substituted five-, six-, and seven-membered ring lactones from internal alkenoic acids

The images from the middle layer of the neural network.

<p><b>(</b>A) Representative color fundus photograph of NDR and an image of the middle layer, which has few characteristics. B-F: Representative color fundus photographs of PDR and their images of the middle layer. (B) Laser scars (white arrow head) were enhanced in the middle image. (C) Hard exudates (white arrow head) were enhanced in the middle image. (D) Soft exudates (white arrow head) were enhanced in the middle image. (E) Proliferative membranes (white arrow head) were enhanced in the middle image. (F) Reflections of the retina (white arrow head) were enhanced in the middle image.</p

A fundus photograph and schema of an eye ball.

<p><b>(</b>A) Posterior pole fundus photograph with proliferative diabetic retinopathy. White arrow head: Neovascularization. Black arrow heads: Soft exudates. Red dots: hemorrhage. (B) Schema of an eye ball. Because there is neovascularization, this eye requires panretinal photocoagulation. Because the neovascularization is not shown in a normal fundus camera field, it could be misdiagnosed as simple diabetic retinopathy, which does not require any therapy.</p

Grading by actual prognosis.

<p>Grading by actual prognosis.</p

The representative fundus photograph which was graded as SDR in one photograph but PDR in four photographs.

<p><b>(</b>A) Horizontal inversion left fundus photograph of DMR showing hemorrhage (white arrow head) and hard exudates (black arrow head) without neovascularization or vitreous hemorrhage. Classification is SDR. (B) Horizontal inversion, composite of four left fundus images showing neovascularization (red arrow head). Classification is PDR. (C) Visualization of the conv2/norm2 layer of the four photograph-trained GoogLeNet. (D) Visualization of the conv2/norm2 layer of GoogLeNet trained by one photograph. Trained network suggested NDR 1% and SDR 99%. Blurry view by the four photograph-trained neural networks; distinct view by the one photograph-trained neural network.</p

Two training methods and a three-patient model.

<p>AI1 was trained on the pairs of one figure and the modified Davis grading of a concatenated figure. AI2 was simply trained on the pairs of one figure and the modified Davis grading of this figure. Red dot: dot hemorrhage representing SDR. Red lightning bolt: neovascularization representing PDR.</p

The images from the middle layer of the neural network.

<p><b>(</b>A) Representative color fundus photograph of NDR and an image of the middle layer, which has few characteristics. B-F: Representative color fundus photographs of PDR and their images of the middle layer. (B) Laser scars (white arrow head) were enhanced in the middle image. (C) Hard exudates (white arrow head) were enhanced in the middle image. (D) Soft exudates (white arrow head) were enhanced in the middle image. (E) Proliferative membranes (white arrow head) were enhanced in the middle image. (F) Reflections of the retina (white arrow head) were enhanced in the middle image.</p