102355-63-5Relevant articles and documents
Stereoselective Synthesis of a Highly Oxygenated δ-Lactone Related to the Core Structure of (-)-Enterocin
Wegmann, Marcus,Bach, Thorsten
supporting information, p. 209 - 217 (2016/12/24)
The title compound was prepared in a concise route starting from an appropriately protected (S)-glyceraldehyde. A highly diastereoselective (d.r. >95:5) Mukaiyama aldol reaction of an acetoacetate-derived silyl enol ether served as the initial step of the synthetic sequence. It was found that protection of the glyceraldehyde as a butane-2,3-dione acetal is required to achieve the desired diastereoselectivity. Upon lactonization, a Tsuji-Trost allylation and a subsequent one-pot reaction cascade including an ozonolysis and an α-hydroxylation gave diastereoselective access to the desired α-hydroxy-β-oxo-δ-lactone. Alternative synthetic approaches are discussed and proof for the configuration of the product is presented.
Ruthenium-catalyzed asymmetric N -demethylative rearrangement of isoxazolidines and its application in the asymmetric total syntheses of (-)-(1 r,3 s)-hpa-12 and (+)-(1 s,3 r)-hpa-12
Xiao, Zu-Feng,Yao, Chuan-Zhi,Kang, Yan-Biao
supporting information, p. 6512 - 6514 (2015/02/19)
An asymmetric N-demethylative rearrangement of 1,2-isoxazolidines catalyzed by ruthenium is described. Enantioenriched syn-1,3-aminoalcohols as well as cis-1,3-oxazinanes, which are useful building blocks, can be efficiently prepared stereospecifically by this reaction in good yields, via the isoxazolidine intermediates in situ generated from a nitrone bearing a chiral auxiliary and styrenes. This asymmetric reaction was also applied in the asymmetric total syntheses of both (-)-(1R,3S)-HPA-12 and (+)-(1S,3R)-HPA-12.
Total synthesis of branimycin: An evolutionary approach
Enev, Valentin S.,Felzmann, Wolfgang,Gromov, Alexey,Marchart, Stefan,Mulzer, Johann
, p. 9651 - 9668 (2012/09/21)
The first total synthesis of the macrolactone antibiotic branimycin (4) has been described. The key disconnection leads to a cis-dehydrodecalone core and a polyketide side chain which are connected via organometallic addition. The dehydrodecalone core was targeted via altogether five different approaches featuring various kinds of chiral elements and ring-closing methodology. In the end the most successful method starting from diepoxynaphthalene 109 was chosen to carry on with the synthesis. Thus the oxygen functions and carbon appendages were introduced via organometallic desymmetrization reactions to generate epoxy ketone 107, to which vinyl iodide 11 was added after conversion into the organolithium species. The synthesis was completed by introducing the ester side chain via Michael addition and subsequent macrolactonization. Competitive approach: The first total synthesis of the macrolactone antibiotic branimycin is described (see figure). The dehydrodecalin core was targeted via five competing approaches featuring various kinds of chiral elements and ring-closing methodology. In this "Darwinian" struggle the most successful route emerged and led to the completion of the synthesis. Copyright
