Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone.

A rhodium-catalyzed intramolecular reductive aldol-type cyclization is described to give ß-hydroxylactones with high diastereoselectivities. The stereoselectivity of this cyclization is highly solvent dependent and can give syn- or anti-ß-hydroxylactones with high diastereoselectivity. This methodology was also applied to the synthesis of a chiral necic acid lactone which is a structural component of the pyrrolizidine alkaloid monocrotaline.

Inter- and Intramolecular Alkyne-Carbonyl Metathesis/1,6-Addition/Oxidative Aromatization Tandem Reactions between 1,6-Diynes and Aldehydes.

We report an efficient synthetic route to 9-arylfluorenes and biaryl compounds from 1,6-diynes and aldehydes via inter- and intramolecular alkyne-carbonyl metathesis/1,6-addition/oxidative aromatization reactions. These tandem reactions are initiated by a BF3·Et2O-promoted tandem inter- and intramolecular alkyne-carbonyl metathesis of 1,6-diynes with carbonyl compounds followed by an In(OTf)3-catalyzed 1,6-addition/oxidative aromatization with iodobenzene diacetate.

Rh-Catalyzed reductive Mannich-type reaction and its application towards the synthesis of (±)-ezetimibe.

An effective synthesis for syn-ß-lactams was achieved using a Rh-catalyzed reductive Mannich-type reaction. A rhodium-hydride complex (Rh-H) derived from diethylzinc (Et2Zn) and a Rh catalyst was used for the 1,4-reduction of an α,ß-unsaturated ester to give a Reformatsky-type reagent, which in turn, reacted with an imine to give the syn-ß-lactam. Additionally, the reaction was applied to the synthesis of (±)-ezetimibe, a potent ß-lactamic cholesterol absorption inhibitor.

Alteromonas gracilis sp. nov., a marine polysaccharide-producing bacterium.

A novel exopolysaccharide-producing bacterium, designated strain 9a2(T), was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase- and catalase-positive, and required NaCl for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile consisted mainly of C16 : 1ω7c, C18 : 1ω9c and C16 : 0. The DNA G+C content was 46.6 mol%. 16S rRNA gene sequence analysis suggested that strain 9a2(T) is a member of the genus Alteromonas . Strain 9a2(T) exhibited closest phylogenetic affinity to Alteromonas macleodii NBRC 102226(T) (99.3% 16S rRNA gene sequence similarity), A. marina SW-47(T) (99.3%), A. litorea TF-22(T) (99.0%), A. australica H17(T) (98.7%), A. simiduii BCRC 17572(T) (98.5%), A. stellipolaris LMG 21861(T) (98.3%) and A. hispanica F-32(T) (98.2%). The DNA-DNA reassociation values between strain 9a2(T) and A. macleodii JCM 20772(T), A. marina JCM 11804(T), A. litorea JCM 12188(T), A. australica CIP 109921(T), A. simiduii JCM 13896(T), A. stellipolaris LMG 21861(T) and A. hispanica LMG 22958(T) were below 70%. Strain 9a2(T) contained phosphatidylethanolamine, phosphatidylglycerol and an unidentified polar lipid. Owing to differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene sequences and DNA-DNA relatedness data, the isolate merits classification as representing a novel species, for which the name Alteromonas gracilis sp. nov. is proposed. The type strain of this species is 9a2(T) ( =JCM 30236(T) =NCIMB 14947(T)).

Psychrobacter oceani sp. nov., isolated from marine sediment.

A novel marine bacterium, designated strain 4k5(T), was isolated from a sediment sample of the Pacific Ocean. The strain was Gram-stain-negative, strictly aerobic, non-motile, oxidase-positive and catalase-positive and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone 8 (Q-8), and its cellular fatty acid profile consisted mainly of C18 : 1v9c (71.4%), C16 : 1v7c (9.1%) and C18 : 0. The DNA G+C content was 45.3 mol%. 16S rRNA gene sequence analysis suggested that strain 4k5(T) is a member of the genus Psychrobacter . Strain 4k5(T) exhibited the closely phylogenetic affinity to Psychrobacter pacificensis IFO 16270(T) (99.4% 16S rRNA gene sequence similarity), P. piscatorii T-3-2(T) (97.7%), P. nivimaris 88/2-7(T) (97.7%), P. celer SW-238(T) (97.7%), P. aestuarii SC35(T) (97.6%) and P. vallis CMS39(T) (97.6%). DNA-DNA hybridization between strain 4k5(T) and P. pacificensis NBRC 103191(T), P. piscatorii JCM 15603(T). P. nivimaris DSM 16093(T), P. celer JCM 12601(T), P. aestuarii JCM 16343(T) and P. vallis DSM 15337(T) was 42.5, 47.0, 38.1, 23.7, 9.0 and 27.4%, respectively. Owing to the significant differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on the 16S rRNA gene sequence and DNA-DNA relatedness data, the isolate merits classification within a novel species, for which the name Psychrobacter oceani sp. nov. is proposed. The type strain is 4k5(T) ( = JCM 30235(T) =NCIMB 14948(T)).

Regioselective iodoazidation of alkynes: synthesis of α,α-diazidoketones.

Aryl alkyl alkynes reacted with N-iodosuccinimide (NIS) and trimethylsilyl azide (TMSN3), leading to α,α-diazidoketones via the regioselective addition of IN3 to alkynes. Huisgen cyclization of α,α-diazidoketones generated bis-triazole compounds.

Ligand-promoted asymmetric imino-Reformatsky reaction of ethyl dibromofluoroacetate.

An enantioselective Reformatsky reaction has been developed for the reaction of ethyl dibromofluoroacetate (1) with an imine. This method represents the first ligand-promoted imino-Reformatsky approach to use a halofluoroacetate. The use of an amino alcohol ligand allowed for the preparation of enantioenriched α-bromo-α-fluoro-ß-lactams in good yields with enantioselectivities up to 96% ee. This process also provided access to ß-lactam rings bearing two stereogenic centers.

Pseudoalteromonas shioyasakiensis sp. nov., a marine polysaccharide-producing bacterium.

A novel exopolysaccharide-producing bacterium, designated strain SE3(T), was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase-positive and catalase-positive, and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile mainly consisted of C16 : 1ω7c, C16 : 0 and C18 : 1ω7c. The DNA G+C content was 46.9 mol%. 16S rRNA gene sequence analysis suggested that strain SE3(T) is a member of the genus Pseudoalteromonas. Strain SE3(T) exhibited close phylogenetic affinity to Pseudoalteromonas arabiensis JCM 17292(T) (99.0 % 16S rRNA gene sequence similarity), Pseudoalteromonas lipolytica LMEB 39(T) (98.39 %) and Pseudoalteromonas donghaensis HJ51(T) (97.65 %). The DNA-DNA reassociation values between strain SE3(T) and P. arabiensis JCM 17292(T), P. lipolytica JCM 15903(T) and P. donghaensis LMG 24469(T) were 31, 26 and 44 %, respectively. Owing to the significant differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene sequences and DNA-DNA relatedness data, the new isolate merits classification as a representative of novel species, for which the name Pseudoalteromonas shioyasakiensis is proposed. The type strain is SE3(T) ( = JCM 18891(T) = NCIMB 14852(T)).

Pseudoalteromonas arabiensis sp. nov., a marine polysaccharide-producing bacterium.

A novel exopolysaccharide-producing bacterium, designated strain k53(T), was isolated from sediment from the Arabia Sea, Indian Ocean. The strain was Gram-negative, motile, strictly aerobic, oxidase-positive and catalase-positive, and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile mainly consisted of C16 : 1ω7c, C16 : 0 and C18 : 1ω7c. The DNA G+C content was 43 mol%. 16S rRNA gene sequence analysis suggested that strain k53(T) is a member of the genus Pseudoalteromonas. Strain k53(T) exhibited close phylogenetic affinity to Pseudoalteromonas lipolytica LMEB 39(T) (98.0% 16S rRNA gene sequence similarity) and Pseudoalteromonas donghaensis HJ51(T) (97.3 %).The DNA-DNA reassociation values between strain k53(T) and P. lipolytica JCM 15903(T) and P. donghaensis LMG 24469(T) were 17 % and 12 %, respectively. Owing to the significant differences in phenotypic and chemotaxonomic characteristics, and phylogenetic analysis based on the 16S rRNA gene sequence and DNA-DNA relatedness data, the isolate merits classification as a representative of a novel species, for which the name Pseudoalteromonas arabiensis is proposed. The type strain of this species is k53(T) ( = JCM 17292(T) = NCIMB 14688(T)).

Regio- and stereoselective multisubstituted enol ester synthesis.

Regio- and stereoselective cohalogenation of alkynes with NXS (X = Br, I) was achieved, and the stereoselectivity of the resulting alkenes was dependent on the substituent on the alkyne. Cohalogenation and successive cross-coupling gave multisubstituted enol esters in a one-pot process.

Indium(III)-catalyzed tandem reaction with alkynylbenzaldehydes and alkynylanilines to heteroaromatic compounds.

Starting from ortho-alkynylbenzaldehydes and ortho-alkynylanilines, In(OTf)3-catalyzed synthesis of ring-condensed heteroaromatic compounds was developed via a domino intramolecular nucleophilic attack/intermolecular cycloaddition/dehydration reaction.

Glaciecola chathamensis sp. nov., a novel marine polysaccharide-producing bacterium.

Two novel exopolysaccharide-producing bacteria, strains S18K6(T) and S18K5, were isolated from Pacific Ocean sediment. The isolates were Gram-negative, motile, strictly aerobic chemoheterotrophic bacteria. The DNA G+C contents of strains S18K6(T) and S18K5 were 44.8 and 46.3 mol%, respectively. DNA-DNA relatedness between the two strains was 70 %. Major fatty acids were hexadecanoic acid (C(16 : 0)), hexadecenoic acid (C(16 : 1)omega7c) and octadecenoic acid (C(18 : 1)omega7c). 16S rRNA gene sequence, chemotaxonomic and morphological data indicated that these strains clearly belonged to the genus Glaciecola. Based on phenotypic properties and DNA-DNA hybridization data, strains S18K6(T) and S18K5 are considered to represent a novel species of the genus Glaciecola, for which the name Glaciecola chathamensis sp. nov. is proposed. The type strain is S18K6(T) (=JCM 13645(T)=NCIMB 14146(T)).

Production of two types of exopolysaccharide by Novosphingobium rosa.

A bacterium, Ikeda-3, that was isolated from the wastewater of a winery was found to produce floating and precipitating exopolysaccharides (EPSs) when grown aerobically in a medium containing sucrose as the sole carbon source. The concentrations of floating and precipitating EPSs were approximately 2.7 g/l and 0.6 g/l, respectively, in a mini-jar fermentor after incubations of the bacterium at 15 degrees C for 5 d in a synthetic medium containing 1% sucrose, 0.01% CaCO3, 0.05% MgSO4, 0.05% K2HPO4, 0.0001% Na2MoO4, 0.05% peptone and 0.82% bicine. A component analysis of two types of EPS suggested that they represent a novel type of sphingan composed of glucose, rhamnose, mannose and mannuroic acid. Glucoronic acid, which is commonly found in sphingans, was absent. From physiological, biochemical and chemotaxonomic characterization, phylogenetic analysis and DNA-DNA relatedness, Ikeda-3 was identified as Novosphingobium rosa. To our knowledge the production of EPS by N. rosa is reported here for the first time.