868547-99-3

Upstream product

• 98-59-9 p-toluenesulfonyl chloride 
• 558-13-4 carbon tetrabromide 
• 183293-41-6 (S)-O-p-toluenesulfonyl-3-hydroxy-2-methylpropanal 
• 84341-89-9 (2S)-(+)-2-methyl-3-(toluene-4-sulfonyloxy)propionic acid methyl ester 

Downstream Products

• 868548-01-0 (4S)-3-[(2S,3R,5S)-2-allyl-3-hydroxy-5-methyl-7-triisopropylsilanylhept-6-ynoyl]-4-benzyloxazolidin-2-one 
• 868548-00-9 toluene-4-sulfonic acid (R)-2-methyl-4-triisopropylsilanylbut-3-ynyl ester 

Relevant academic research and scientific papers

High π-Facial and exo-Selectivity for the Intramolecular Diels-Alder Cycloaddition of Dodeca-3,9,11-trien-5-one Precursors to 2-epi-Symbioimine and Related Compounds

An unconstrained exocyclic stereogenic center and a removable trimethylsilyl group are combined to induce high π-facial selectivity and near-exclusive exo-selectivity in the intramolecular Diels-Alder cycloaddition of dodeca-3,9,11-trien-5-ones. This strategy provides direct access to polysubstituted trans-1-decalones related to the symbioimines in good yield and acceptable diastereoselectivity.

Domino intramolecular enyne metathesis/cross metathesis approach to the xanthanolides. Enantioselective synthesis of (+)-8-epi-xanthatin

The first total synthesis of (+)-8-epi-xanthatin (1) has been achieved in 14 steps starting from the commercially available ester 24, which was converted into aldehyde 23 in six steps. An enantioselective aldol reaction of 23 gave 30, which was transformed into triflate 22 in four steps, setting the stage for a palladium-catalyzed carbonylation reaction to form acrylate 34. Compound 34 was then subjected to a deprotection/lactonization sequence to furnish enyne 21, which underwent a domino enyne ring-closing metathesis/cross metathesis process to form a seven-membered carbocycle and (E)-conjugated dienone, thereby completing the synthesis of 1. This domino ruthenium-catalyzed metathesis reaction thus serves as an efficient method to construct the core of xanthanolide and other sesquiterpene lactones.

Application of a domino intramolecular enyne metathesis/cross metathesis reaction to the total synthesis of (+)-8-epi-xanthatin

(Chemical Equation Presented) The first total synthesis of the novel sesquiterpene lactone (+)-8-epi-xanthatin (1) has been achieved starting from the commercially available ester 8. The synthesis features an asymmetric aldol reaction and palladium-catalyzed carbonylation/lactonization sequence leading to 4 and a domino ring-closing enyne metathesis/cross metathesis reaction to afford 1.