Acylammonium Salts as Dienophiles in Diels–Alder/Lactonization Organocascades
datasetposted on 17.12.2015 by Mikail E. Abbasov, Brandi M. Hudson, Dean J. Tantillo, Daniel Romo
Datasets usually provide raw data for analysis. This raw data often comes in spreadsheet form, but can be any collection of data, on which analysis can be performed.
α,β-Unsaturated acylammonium salts, generated in situ from commodity acid chlorides and a chiral isothiourea organocatalyst, comprise a new and versatile family of chiral dienophiles for the venerable Diels–Alder (DA) cycloaddition. Their reactivity is unveiled through a highly diastereo- and enantioselective Diels–Alder/lactonization organocascade that generates cis- and trans-fused bicyclic γ- and δ-lactones bearing up to four contiguous stereocenters. Moreover, the first examples of DA-initiated, stereodivergent organocascades are described delivering complex scaffolds found in bioactive compounds. The origins of stereoselectivity are rationalized through computational studies. In addition, the utility of this methodology is demonstrated through a concise approach to the core structure of glaciolide and formal syntheses of fraxinellone, trisporic acids, and trisporols.