Stripping off water at ambient temperature: direct atom-efficient acetal formation between aldehydes and diols catalyzed by water-tolerant and recoverable vanadyl triflate.
[reaction: see text]. Aromatic aldehydes can be readily protected as acetals with 1,2- and 1,3-diols by using vanadyl triflate as a catalyst in CH(3)CN at ambient temperature. Carbohydrate-based 1,2- and 1,3-diols can similarly be protected in good to excellent yields. The catalyst can be readily recovered from the aqueous layer. In combination with vanadyl triflate-catalyzed sequential regioselective, reductive acetal opening and chemoselective acylations, the title method allows for differential functionalization of all four hydroxyl units in a given glucopyranoside.
Chen
Chien-Tien
CT
Department of Chemistry, National Taiwan Normal University, Academia Sinica, Taipei. chefv043@scc.ntnu.edu.tw
Weng
Shiue-Shien
SS
Kao
Jun-Qi
JQ
Lin
Chun-Cheng
CC
Jan
Mi-Dan
MD
D000080:Acetals / Q000138:chemical synthesis*; D000438:Alcohols / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D005960:Glucosides / Q000737:chemistry*; D008698:Mesylates / Q000737:chemistry; D015394:Molecular Structure; D013696:Temperature; D014638:Vanadates / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D000080:Acetals; D000438:Alcohols; D000447:Aldehydes; D005960:Glucosides; D008698:Mesylates; C510339:vanadyl triflate; D014867:Water; D014638:Vanadates