title: Application of Carbohydrate-Templated Asymmetric Diels-Alder Reaction to the Syntheses of ent-Penicillones A and B.
abstract: Total syntheses of ent-penicillones A (ent-1) and B (ent-2) from 3,5-dimethylcatechol (3) were accomplished in 10 and 9 synthetic steps, respectively. A carbohydrate-templated asymmetric intramolecular Diels-Alder reaction of a masked o-benzoquinone (MOB) 9 and an aqueous acid-catalyzed intramolecular aldol reaction are the key synthetic steps. In addition, the absolute configurations of the bicyclo[2.2.2]oct-5-en-2-one core obtained from the per-O-benzylated α-d-glucopyranosyl as a carbohydrate template in the intramolecular Diels-Alder reaction of MOBs were revised.
authors.affiliation: Department of Chemistry, National Tsing Hua University , Hsinchu, 300, Taiwan.
authors.forename: Chia-Hao
authors.initials: CH
authors.lastname: Weng
authors.affiliation: Department of Chemistry and Biochemistry, National Chung Cheng University , Minhsiung, 621, Taiwan.
authors.forename: Day-Shin
authors.initials: DS
authors.lastname: Hsu
authors.affiliation: Department of Chemistry, National Tsing Hua University , Hsinchu, 300, Taiwan.|Department of Chemistry, Chung Yuan Christian University , Chungli, 320, Taiwan.
authors.forename: Chun-Chen
authors.initials: CC
authors.lastname: Liao
mesh_terms: D016227:Benzoquinones / Q000737:chemistry; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry*; D002384:Catalysis; D002396:Catechols / Q000737:chemistry; D061565:Cycloaddition Reaction; D006031:Glycosylation; D007536:Isomerism; D015394:Molecular Structure; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D016227:Benzoquinones; D002241:Carbohydrates; D002396:Catechols; D011753:Pyrones; C523611:penicillone; C025225:2-benzoquinone