Practical synthesis of 2,5-disubstituted 1,3-dioxolane-4-ones and highly diastereoselective cis-2,5-disubstituted 1,3-dioxolane-4-ones from α-hydroxy acids catalyzed by N-triflylphosphoramide

An organocatalytic method for the synthesis of some novel xanthene derivatives by the intramolecular Friedel–Crafts reaction

“…A study on this subject includes the preparation of 1,3dioxolane-4-ones starting from a-hydroxy acids and aldehydes with the use of 3g. 25 Another example reports a transformation, which has merged the Ugi reaction and Houben-Hoesch cyclisation in the presence of 3g. 26 In that report, aer several Brønsted and Lewis acids were examined, they found that the acid-promoted reaction is effective in the synthesis of many 3aminoindole molecules using 3g with high yields and under mild conditions.…”