Diastereoselective Synthesis of Pentasubstituted γ-Butyrolactones from Silyl Glyoxylates and Ketones through a Double Reformatsky Reaction

Three contiguous stereocenters can be established with remarkable diastereoselectivity in a double Reformatsky sequence. Densely functionalized gamma-butyrolactones were assembled rapidly by this approach, in which a ketone is used as the terminal electrophile (see scheme). Secondary transformations of the lactone products enhance their synthetic utility. R(1) = Me, H; R(2) = alkyl, aryl, CF(3); Bn = benzyl, TBS = tert-butyldimethylsilyl

Catalytic Redox-Initiated Glycolate Aldol Additions of Silyl Glyoxylates

Lanthanide triisopropoxides catalyze a rapid, tandem MPV reduction/Brook rearrangement/aldol sequence between silyl glyoxylates and aldehydes that achieves catalytic turnover through alkoxide transfer from a strain-release Lewis acidic silacycle

Formal Synthesis of Leustroducsin B via Reformatsky/Claisen Condensation of Silyl Glyoxylates

A formal synthesis of leustroducsin B has been completed. The synthesis relies upon a recently developed Reformatsky/Claisen condensation of silyl glyoxylates and enantioenriched β-lactones that establishes two of the molecule's three core stereocenters and permits further elaboration to an intermediate in Imanishi's synthesis via reliable chemistry (Prasad reduction, asymmetric pentenylation, Mitsunobu inversion)

Remote Stereoinduction in the Acylation of Fully Substituted Enolates: Tandem Reformatsky/Quaternary Claisen Condensations of Silyl Glyoxylates and β-Lactones

Reformatsky reagents react sequentially with silyl glyoxylates and β-lactones to give highly functionalized Claisen condensation products. A heretofore undocumented instance of stereochemical 1,4-induction results in efficient transmission of β-lactone stereochemistry to the emerging fully-substituted stereocenter. Second-stage transformations reveal that the five heteroatom-containing functionalities embedded within the products are entirely chemo-differentiated, a circumstance that permits rapid assembly of the leustroducsin B core substructure

Silyl Glyoxylates. Conception and Realization of Flexible Conjunctive Reagents for Multicomponent Coupling

This Perspective describes the discovery and development of silyl glyoxylates, a new family of conjunctive reagents for use in multicomponent coupling reactions. The selection of the nucleophilic and electrophilic components determines whether the silyl glyoxylate reagent will function as a synthetic equivalent to the dipolar glycolic acid synthon, the glyoxylate anion synthon, or the α-keto ester homoenolate synthon. The ability to select for any of these reaction modes has translated to excellent structural diversity in the derived three- and four-component coupling adducts. Preliminary findings on the development of catalytic reactions using these reagents are detailed, as are the design and discovery of new reactions directed toward particular functional group arrays embedded within bioactive natural products