Synthesis of epoxyquinol A and related molecules: probing chemical reactivity of epoxyquinol dimers and 2H-pyran precursors.
Total syntheses of the epoxyquinoid dimers, epoxyquinols A, B, and epoxytwinol A (RKB-3564 D), have been accomplished employing [4 + 2] and [4 + 4] dimerization of 2H-pyran epoxyquinol monomers. Modifications of 2H-pyran precursors have been explored, including alteration of epoxy alcohol and diene stereochemistry. A stable 2H-pyran prepared by alteration of the epoxyquinol 2H-pyran nucleus was evaluated as a diene in Diels-Alder cycloaddition with reactive dienophiles. Extensive studies for improving the [4 + 4] dimerization of selectively protected 2H-pyran monomers to afford the novel epoxyquinoid dimer epoxytwinol A were carried out, and valuable insight regarding competitive [4 + 2] and [4 + 4] dimerization processes has been obtained. In addition, chemical reactivities and structural modifications of epoxyquinol dimers have been evaluated, including [2 + 2] photocycloaddition and [3,3] sigmatropic rearrangement, indicating the possibility for production of novel structural diversity from dimeric epoxyquinoid natural product frameworks.
Li
Chaomin
C
Department of Chemistry and Center for Chemical Methodology and Library Development, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA.
Porco
John A
JA
D000438:Alcohols / Q000737:chemistry; D000466:Alkadienes / Q000737:chemistry; D040761:Biomimetic Materials / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D019281:Dimerization; D004852:Epoxy Compounds / Q000138:chemical synthesis*; D006873:Hydroquinones / Q000138:chemical synthesis*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D011714:Pyrans / Q000737:chemistry*; D013237:Stereoisomerism
D000438:Alcohols; D000466:Alkadienes; D004852:Epoxy Compounds; D006873:Hydroquinones; D011714:Pyrans; C455959:epoxyquinol A; C469247:epoxyquinol B; C496191:epoxytwinol A