title: Functionalizing the γ-Position of α-Diazo-β-ketoesters.
abstract: Although α-diazo-β-ketoesters are synthetically versatile intermediates, methodology for introducing this functionality into complex molecules is still limited, most frequently involving a carboxylic acid precursor, which is then activated and transformed into a β-ketoester, with the diazo group being subsequently added with a diazo transfer reagent. While introducing this highly functional moiety in a convergent one step process would be ideal, such an objective is limited by the relatively few studies which address functionalization of the α-diazo-β-ketoester at the γ-position. In the present investigation, we evaluate strategies, both new and established, for functionalizing α-diazo-β-ketoesters, particularly with regard to generating compounds prospectively useful in the synthesis of C1-substituted carbapenems. We report the first δ-aldehydo-α-diazo-β-ketoester as well as a method for its oxidation to the corresponding methyl ester, and the formation of a new substituted pyrazole under basic conditions.
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Thu Q
authors.initials: TQ
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Maha
authors.initials: M
authors.lastname: Alqurafi
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Cash
authors.initials: C
authors.lastname: Edwards
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Pauline
authors.initials: P
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Jean
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Casco
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Maricka
authors.initials: M
authors.lastname: Bennet
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Chiang
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Maureen
authors.initials: M
authors.lastname: Lohry
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Melina
authors.initials: M
authors.lastname: Cox
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Byron
authors.initials: B
authors.lastname: Meshram
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Duyen
authors.initials: D
authors.lastname: Le
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: Snigdha
authors.initials: S
authors.lastname: Smriti
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, 309 East Second St., Pomona, California, 91768, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Oelschlaeger
authors.affiliation: Department of Chemistry, Southern Methodist University, Dallas, TX, 75275-0314 USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Buynak
keywords: Diazo; carbapenem; pyrazole; β-ketoester