Benzylidene acetal
{{Short description|Functional group}}
In organic chemistry, a benzylidene acetal is the functional group with the structural formula C6H5CH(OR)2 (R = alkyl, aryl). Benzylidene acetals are used as protecting groups in glycochemistry.{{cite journal|author=David Crich|title=Mechanism of a Chemical Glycosylation Reaction|journal=Acc. Chem. Res.|year=2010|volume=43|issue=8|pages=1144–1153|doi=10.1021/ar100035r|pmid=20496888}}
{{cite journal|title=6-Bromo-6-deoxy Hexose Derivatives By Ring Opening Of Benzylidene Acetals With N-bromosuccinimide: Methyl 4-o-benzoyl-6-bromo-6-deoxy-α-d-glucopyranoside|author=S. Hanessian|journal=Org. Synth.|year=1987|volume=65|page= 243|doi=10.15227/orgsyn.065.0243}} These compounds can also be oxidized to carboxylic acids in order to open important biological molecules, such as glycosaminoglycans, to other routes of synthesis.{{Cite journal|last=Banerjee|first=Amit|last2=Senthilkumar|first2=Soundararasu|last3=Baskaran|first3=Sundarababu|date=2015-12-07|title=Benzylidene Acetal Protecting Group as Carboxylic Acid Surrogate: Synthesis of Functionalized Uronic Acids and Sugar Amino Acids|journal=Chemistry - A European Journal|language=en|volume=22|issue=3|pages=902–906|doi=10.1002/chem.201503998|pmid=26572799|issn=0947-6539}} They arise from the reaction of a 1,2- or 1,3-diols with benzaldehyde. Other aromatic aldehydes are also used.{{cite journal|title=Protection Of Diols With 4-(Tert-butyldimethylsilyloxy)benzylidene Acetal And Its Deprotection |author=Hiroyuki Osajima |author2=Hideto Fujiwara |author3=Kentaro Okano |author4=Hidetoshi Tokuyama |author5=Tohru Fukuyama|journal=Org. Synth.|date=2009|volume=86|page=130|doi=10.15227/orgsyn.086.0130|doi-access=free}}