72258-18-5Relevant academic research and scientific papers
Sensing remote chirality: Stereochemical determination of β-, γ-, and δ-chiral carboxylic acids
Tanasova, Marina,Anyika, Mercy,Borhan, Babak
supporting information, p. 4274 - 4278 (2015/04/14)
Determining the absolute stereochemisty of small molecules bearing remote nonfunctionalizable stereocenters is a challenging task. Presented is a solution in which appropriately substituted bis(porphyrin) tweezers are used. Complexation of a suitably derivatized β-, γ-, or δ-chiral carboxylic acid to the tweezer induces a predictable helicity of the bis(porphyrin), which is detected as a bisignate Cotton Effect (ECCD). The sign of the ECCD curve is correlated with the absolute stereochemistry of the substrate based on the derived working mnemonics in a predictable manner.
Concise epoxide-based synthesis of the C14-C25 bafilomycin A1 polypropionate chain
Valentín, Elizabeth M.,Mulero, Marlenne,Prieto, José A.
supporting information; experimental part, p. 2199 - 2201 (2012/05/19)
An efficient nonaldol convergent synthesis of the C14-C25 polyketide fragment of bafilomycin A1 was completed in 16% overall yield and 8 steps in its longest linear sequence. This synthesis highlights the formation of the key fragments using a
Absolute stereostructure and total synthesis of leptomycin B
Kobayashi, Motomasa,Wang, Weiqi,Tsutsui, Yasuhiro,Sugimoto, Masanori,Murakami, Nobutoshi
, p. 8291 - 8294 (2007/10/03)
The absolute stereostructure of leptomycin B, an antitumor antibiotic and inhibitor of nuclear protein export, was firstly presumed as 1 having 4S, 5R, 10R, 16R, 18S, 19R, 20S on the basis of NMR comparison with callystatin A (2) and then 1 was asymmetric
REACTION OF DIANIONS DERIVED FROM β-KETOESTERS WITH EPOXIDES - UTILITY IN THE PREPARATION OF SYNTHETICALLY USEFUL TETRAHYDROFURANS.
Lygo, Barry,O'connor, Norval,Wilson, Peter R.
, p. 6881 - 6888 (2007/10/02)
Presented here are several examples which demonstrate that ether substituents α- or β- to an epoxide ring can be tolerated in the ring-opening reaction with β-keto ester dianions.Subsequent acid-promoted cyclisation of the γ-hydroxy β-ketoesters then leads to synthetically useful tetrahydrofurans, as demonstrated by application of this approach to the preparation of (+/-)-methyl nonactate and (+/-)-methyl 8-epi-nonactate.
SYNTHESIS OF THE ENANTIOMERIC FORMS OF CIS AND TRANS 1-BENZYLOXY-2,3-EPOXY BUTANE AND OF (3S,4S) 4-METHYL-3-HEPTANOL
Fuganti, Claudio,Grasselli, Piero,Servi, Stefano,Zirotti, Carlo
, p. 4269 - 4272 (2007/10/02)
The C4 erythro and threo diols (7) and (8) are converted either into the chiral epoxides (13) and (15) or into the enantiomers (14) and (16); the epoxide (13) is used as chiral synthon for the preparation of (3S,4S) 4-methyl-3-heptanol (21).
Enantiomerically Pure Synthetic Building Blocks with Four C-Atoms and Two or Three Functional Groups from β-Hydroxy-butanoic, Malic, and Tartaric Acid
Hungerbuehler, Ernst von,Seebach, Dieter,Wasmuth, Daniel
, p. 1467 - 1487 (2007/10/02)
The pool of chiral, non-racemic electrophilic building blocks, which are available from simple natural products in both enantiomeric forms is enlarged by the epoxides 3, 5, and 10, by the tosylate 12a, and by the aldehydes 18 (cf. symbols A-D, 14, and Scheme 1).Key steps of the conversions leading from hydroxyacids to the building blocks are: epoxide-opening by triethylborohydride (1 --> 2a) and tosylate reduction (12a --> 12b); the Mitsunobu inversion (2a --> 4a); the reduction of (R,R)-tartaric ester to (R)-malic ester by NBS (N-bromosuccinimide) opening of the benzaldehyde acetal 8 and tin hydride reduction (6c -->7c); the enantiomer enrichment of optically active ethyl β-hydroxy-butanoate through the crystalline dinitrobenzoate 21b.Detailed procedures are given for large scale preparations of the key intermediates.The enantiomeric purities of the building blocks are secured by correlations.
