About: http://webisa.webdatacommons.org/256669313

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Preferably, R4 is an alkylene group, such as methylene or an dimethylmethylene.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com