The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《A novel synthesis of (R)- and (S)-4-hydroxytetrahydrofuran-2-ones》. Authors are Tanaka, Akira; Yamashita, Kyohei.The article about the compound:(R)-4-Hydroxydihydrofuran-2(3H)-onecas:58081-05-3,SMILESS:O=C1OC[C@H](O)C1).Application In Synthesis of (R)-4-Hydroxydihydrofuran-2(3H)-one. Through the article, more information about this compound (cas:58081-05-3) is conveyed.
The hydroxy ester I (R = H, R1 = OH), prepared from L-ascorbic acid by sequential treatment with acetone and AcCl, 30% H2O2 and CaCO3, and Me2SO4, was treated with MeSO2Cl and pyridine in CH2Cl2 to give 90% I (R = H, R1 = MeSO3), which, when heated at 85° with LiCl in DMF furnished a mixture of the erythro and threo chloro esters I (R = Cl, R1 = H; R = H, R1 = Cl) (II). Upon hydrogenolysis with 10% Pd/C in the presence of Et3N, II yielded the ester I (R = R1 = H), which was treated with dilute HCl giving a nearly quant. yield of hydroxylactone III. The (S)-enantiomer was analogously prepd from D-isoascorbic acid.
After consulting a lot of data, we found that this compound(58081-05-3)Application In Synthesis of (R)-4-Hydroxydihydrofuran-2(3H)-one can be used in many types of reactions. And in most cases, this compound has more advantages.
Reference:
Pyrroline – Wikipedia,
1-Pyrroline | C4H7N – PubChem