197016-08-3

Upstream product

• 197016-07-2 (2R,4S)-5-(acetyloxy)-2,4-dimethylpentyl phenyl sulfone 
• 873-55-2 sodium benzenesulfonate 
• 197016-06-1 (2S,4R)-5-iodo-2,4-dimethylpentan-1-ol acetate 
• 90270-02-3 (2R,4S)-1-hydroxy-2,4-dimethylpentyl acetate 

Downstream Products

• 545445-73-6 (3S,5R,8R,10S)-6-Acetoxy-7-benzenesulfonyl-11-(tert-butyl-dimethyl-silanyloxy)-3,5,8,10-tetramethyl-undecanoic acid methyl ester 
• 197016-10-7 (3S,5R,8R,10S)-7-Benzenesulfonyl-11-(tert-butyl-dimethyl-silanyloxy)-6-hydroxy-3,5,8,10-tetramethyl-undecanoic acid methyl ester 
• 197016-00-5 (2R,4S)-5-{[(tert-butyl)dimethylsilyl]oxy}-2,4-dimethylpentyl phenyl sulfone 

Relevant academic research and scientific papers

Formal synthesis of borrelidin: A highly enantio- and diastereoselective access to the Morken's C2-C12 intermediate

In contrast to methyl and isobutyl phenyl sulfone, condensing under basic conditions higher alkyl sulfones and trans-2,3-epoxy-butanol 13c (or its O-benzyl and O-silyl derivatives) proved unfeasible, a difficulty that was overcome by using mono ethers of trans-2,3-epoxy-butane-1,4-diol 35c as the electrophilic reagents. Thus, adding excess BuLi to a mixture of the benzyl ether 35b and sulfone ent-12a, a stereodiad sulfone prepared in pure state from the R-Roche ester, via the O-trityloxy-sulfone ent-12c (X-ray), gave, after elimination by column chromatography of the side-formed regioisomer, a diolsulfone that was next converted to sulfone 20 by means of conventional functional-group modifications. Reacting like-wise this sulfone with the parent O-PMB derivative 35a, and then proceeding to the same purification process and function adjustment, delivered the title fragment in virtually pure state.

Synthesis of a conformationally flexible β-hairpin mimetic

Rational conformation design led us to a synthesis of the ω-amido-undecenamide 4, which was shown by theoretical means (simulated annealing techniques) and by NMR and IR spectroscopy to have a high tendency to populate a conformation corresponding to a natural β-II′-type hairpin, despite possessing a conformationally fully flexible open-chain backbone.

Conformation design of a fully flexible βII-hairpin analogue

Almost congruent with the natural prototype 1, βII-hairpin mimetic 2 was obtained through rational conformation design. The hydrocarbon backbone of 2 provides optimal preorganization of the hydrogen bond, which is decisive for inducing a β-sheet conformation.