title: Synthesis of acyclic ketones by catalytic, bidirectional homologation of formaldehyde with nonstabilized diazoalkanes. Application of a chiral diazomethyl(pyrrolidine) in total syntheses of erythroxylon alkaloids.
abstract: This work offers a catalytic approach to convergent ketone assembly based upon formal and tandem C-H insertion of diazoalkanes in the presence of limiting amounts of monomeric formaldehyde, which is easily generated as a gas by thermolysis of the inexpensive and abundant paraformaldehyde (∼30 USD/kg). The method forms di-, tri-, and even tetrasubstituted acetones with high efficiency, and it has streamlined a synthesis of (-)-dihydrocuscohygrine in which the absolute stereochemistry of a proline-based starting material is preserved. Assisted by the advent of new protocols for hydrazone oxidation, we also provide full details on handling non-carbonyl-stabilized diazo compounds.
authors.affiliation: Department of Chemistry, Eugene F. Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Wommack
authors.forename: Jason S
authors.initials: JS
authors.lastname: Kingsbury
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D002384:Catalysis; D005557:Formaldehyde / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000473:Alkanes; D001372:Aza Compounds; D007659:Ketones; D005557:Formaldehyde