Highly efficient substrate and reagent controlled stereoselective synthesis of 2,6-trans-piperidine derivative (1) using an aza-Michael reaction is reported. This method was utilized to synthesize a variety of trans-piperidines on hundred-gram scales. (C) 2018 Elsevier Ltd. All rights reserved.

We have tested a number of synthetic methods for large-scale synthesis of targeted substituted aromatic alkyne (S)-[4-(3-chloro-5-ethynyl-4-fluoro-phenyl)-1-methyl-butyl]-carbamic acid benzyl ester (1). This research resulted in an improved method for the Corey-Fuchs approach to alkyne synthesis from aldehydes. Importantly, we have shown that the use of P(OCH3)(3)/CBr4 in toluene for the synthesis of the dibromo-methylene intermediate (S)-{4-[3-chloro-5-(2,2-dibromo-vinyl)-4-fluoro-phenyl]-1-methyl-butyl}-carbamic acid benzyl ester (5) allows the synthesis of alkyne 1 under conditions that may be amenable for scaling-up. Since this method was developed, multiple batches of alkyne 1, each approaching 100 g in size, have been prepared under process-friendly conditions, as well as multigram batches of other alkynes.

L'invention concerne, d'une maniere generale, le domaine des composes anti-microbiens ainsi que des procedes permettant de les fabriquer et de les utiliser. Ces composes sont utiles pour traiter, prevenir et reduire le risque d'infections microbiennes chez des etres humains et chez des animaux.

We have developed a first generation of hybrid sparsomycin–linezolid compounds into a new family of orally bioavailable biaryloxazolidinones that have activity against both linezolid-susceptible and -resistant Gram-positive bacteria as well as the fastidious Gram-negative bacteria Haemophilus influenzae and Moraxella catarrahalis. The convergent synthesis of these new compounds is detailed.

From the X-ray crystal structures of linezolid and the non-selective antibiotic sparsomycin, we have derived a new family of hybrid oxazolidinones. From this initial compound set we have developed a new biaryloxazolidinone scaffold that shows both potent antimicrobial activity as well as selective inhibition of ribosomal translation. The synthesis of these compounds is outlined.

La presente invention concerne en general le secteur des agents anti-infectieux, anti-proliferants, anti-inflammatoires et procinetiques. Plus particulierement, l’invention concerne une famille de composes tri-cycliques utilises en tant qu'agents de ce type.

3-O-Allylcarbohydrate nitrone cycloaddition (3-OACNC) furnished pyran and oxepane derivatives from 3-O-allyl hexose N-benzyl nitrones and 3-O-allyl furanoside-5-aldehyde N-benzyl/methyl nitrones. The regioselectivity of 3-OACNC was found to depend on the following factors (a) the structural nature of the nitrone (b) substitution and stereochemistry at 3-C of the carbohydrate backbone (c) substitution at the terminus of the O-allyl moiety. Oxepanes or pyrans obtained from a particular set of a hexose nitrone and the corresponding furanoside nitrone were converted to enantiomeric cyclic ethers through degradation. A mixture of an oxepane and a pyran was formed in the intramolecular oxime olefin cycloaddition (IOOC) of a 3-O-allylcarbohydrate derived oxime.

[structure: see text] A convergent, stereoselective assembly of the C1-C21 (C1'-C21') fragment of SCH 351448, a 28-membered bis-lactone natural product, has been developed. A highly efficient approach to this fragment assembles 75% of the carbon skeleton and all the stereochemical elements present in the natural product. In addition, an interesting boron ligand effect on the diastereoselectivity of a key aldol reaction with methyl ketone-derived enolborinates is reported.

The first total synthesis of the potent cytostatic agent apicularen A is described along with the synthesis of the corresponding C11-epimers and side chain modified congeners. Growth inhibition experiments with the human melanoma cancer cell line SK-MEL-5 revealed an important role for the unusual N-acyl enamide side chain.

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Chiral nonracemic pyranocyclohexanes 7 and 8 and oxepanocyclohexane 11 and 12 were obtained from a single 1,2-isopropylidene-3-O-cyclohesenyl carbohydrate aldehyde 4 via intramolecular nitrile oxide cycloaddition. and were converted to 2-(2'-tetrahydrofuryl)pyran 28, which incorporates the lasalocid skeleton. and the related oxepane derivative 32 respectively, through modification of the furanoside ring by applying 2-O-allyl carbohydrate nitrone cycloaddition: (C) 1999 Elsevier Science Ltd. All rights reserved.

The intramolecular cycloaddition of nitrones derived from 3- O -cyclohexenylfuranoside-5-aldehydes led to diastereoselective formation of tetrahydropyrano[2,3]cyclohexane ring systems with six chiral centres.