811867-69-3Relevant articles and documents
One-handed helical screw direction of homopeptide foldamer exclusively induced by cyclic α-amino acid side-chain chiral centers
Demizu, Yosuke,Doi, Mitsunobu,Kurihara, Masaaki,Maruyama, Tokumi,Suemune, Hiroshi,Tanaka, Masakazu
supporting information; experimental part, p. 2430 - 2439 (2012/03/27)
Chiral cyclic α,α-disubstituted amino acids, (3S,4S)- and (3R,4R)-1-amino-3,4-(dialkoxy)cyclopentanecarboxylic acids ((S,S)- and (R,R)-Ac5cdOR; R: methyl, methoxymethyl), were synthesized from dimethyl L-(+)- or D-(-)-tartrate, and their homochiral homoligomers were prepared by solution-phase methods. The preferred secondary structure of the (S,S)-Ac5cdOMe hexapeptide was a left-handed (M) 3 10 helix, whereas those of the (S,S)-Ac5cdOMe octa- and decapeptides were left-handed (M) α helices, both in solution and in the crystal state. The octa- and decapeptides can be well dissolved in pure water and are more α helical in water than in 2,2,2-trifluoroethanol solution. The left-handed (M) helices of the (S,S)-Ac5c dOMe homochiral homopeptides were exclusively controlled by the side-chain chiral centers, because the cyclic amino acid (S,S)-Ac 5cdOMe does not have an α-carbon chiral center but has side-chain γ-carbon chiral centers. Copyright