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A novel and highly enantioselective synthesis of hydroxyalkynyl esters and ethers through the asymmetric addition of alkynyl esters or ethers to aldehydes promoted by a cyclopropyl amino alcohol based zinc catalyst has been developed. The method afforded a library of new enantioenriched hydroxyalkynol esters and ethers (up to 93% yield; 95% ee), and it was compatible with a broad range of functional groups. Moreover, it could be used in the synthesis of carbon-chain-elongated enantioenriched hydroxyalkynol esters and (2R,5R)-musclide-A1, a cardiotonic potentiating principle from musk.

Leukotriene B4 1 was prepared from two chiral synthons 8 and 14. The chiral secondary alcohols of 8 and 14 were constructed by BINOL/Ti(OiPr)4 catalyzed enantioselective alkynylzinc addition to aldehydes.

The first asymmetric catalytic synthesis of (−)-oudemanisin A 1a and its diastereomer 1b has been achieved. The key steps of our strategy involved the asymmetric alkynylation of an unsaturated aliphatic aldehyde catalyzed by Trost’s ProPhenol ligand, chemoselective oxidation of the olefinic diol, base-induced ring opening of the lactone, and acylation–alkylation of the ester.

The first total syntheses of 9-epoxyfalcarindiol 1a and its diastereomer 1b have been achieved. Central to our approach were the Zn-cyclopropane-based amino alcohol catalyzed enantioselective alkynylation of acrolein, the diastereoselective addition of a diynic ester to an epoxy aldehyde, and the asymmetric Sharpless epoxidation of allylic alcohol catalyzed with L-(+)-diethyl tartrate and Ti(OiPr)4.

The first enantioselective synthesis of (2 R ,13 R ,8 Z )-2,13-diacetoxy-8-heptadecene 1 , the major component of the sex pheromone of the pear leaf midge, Dasineura pyri , has been achieved. The key steps include the ( R , R )-BINOL/Ti(O i Pr) 4 catalyzed alkynylzinc addition to an unsaturated aldehyde, the ring-opening of the chiral epoxide with a Grignard reagent, and the partial reduction of an acetylenic diol ester to a ( Z )-olefinic diol ester with hydrogen and P2-Ni.

An efficient synthesis of panaxytriol and its seven stereoisomers was achieved, and four unnatural diastereomers of 2a were prepared. The key steps involved the opening of vicinal hydroxy epoxides, the stereospecific opening of the epoxides with perchloric acid, and the Cadiot–Chodkiewicz cross-coupling of chiral terminal alkynes with bromoalkynes. Preliminary antitumor activity investigations indicated that some synthetic panaxytriols exhibited promising cytotoxic activity against three human cancer cell lines.

An efficient total synthesis of natural panaxydol 1a and its seven stereoisomers 1b – h was accomplished; four diastereomers of the natural form were prepared for the first time. Our strategy involves the Cadiot-Chodkiewicz cross-coupling reaction of chiral terminal alkynes with bromoalkynes, the asymmetric alkynylation of aldehydes, and the enantioselective Sharpless epoxidation of allylic alcohols. Preliminary in vitro cytotoxicity evaluation indicated that some synthetic panaxydols possess anticancer activities, and (3 S ,9 R ,10 S )-panaxydol 1e showed a particularly promising cytotoxic effect.

An efficient enantioselective total synthesis of an antitumor marine natural product ( S ,4 E ,15 Z )-docosa-4,15-dien-1-yn-3-ol 1 with 96% ee and 15% overall yield has been achieved; this is the first preparation of 1 via asymmetric catalytic strategy. The key steps involve the asymmetric addition of trimethylsilylacetylene to a diolefinc aldehyde using a ( R , R )-ProPhenol ligand and a zipper reaction of an alkyne.

A concise and highly enantioselective (>99% ee) synthesis of falcarinol and panaxjapyne A and their enantiomers has been accomplished. The key steps involve the asymmetric addition of alkynylzinc reagent to acrolein and propionaldehyde catalyzed by a BINOL–Ti(O i Pr) 4 complex and a classic Cadiot–Chodkiewicz cross-coupling reaction. The chiral polyacetylenic alcohols synthesized herein have potential utility in the development of antitumor drugs and antidiabetic agents.

A mild, concise, and highly enantioselective (93% ee) synthesis of Japonilure and its enantiomer, Anomala osakana pheromone, is described. The key steps involve the asymmetric addition of methyl propionate to undec-2-ynal with a Zn-ProPhenol catalyst and the selective and partial reduction of the diynol ester to the cis-enol ester with Brown’s P2-Ni catalyst, providing the first synthesis of the enol ester via semi-hydrogenating diynol ester.

An efficient catalytic asymmetric synthesis of the CPB pheromone [(S)-1,3-dihydroxy-3,7-dimethyl-6-octen-2-one] and its enantiomer was accomplished with 99% ee and in gram quantities from geraniol. The key steps in this procedure involve Sharpless asymmetric epoxidation and recrystallization of the 4-bromobenzoate from the CPB pheromone to improve its enantiomeric purity. Furthermore, the absolute configuration of the CPB pheromone enantiomer was confirmed as (R) for the first time by the X-ray crystallographic structure of its benzoate.

The first total syntheses of two marine natural products, (R)-strongylodiols C and D, with 99% ee were achieved. The key steps of the strategy include the zipper reaction of an alkyne, the asymmetric alkynylation of an unsaturated aliphatic aldehyde catalyzed with Trost's ProPhenol ligand, and the Cadiot-Chodkiewicz cross-coupling reaction of a chiral propargylic alcohol with a bromoalkyne.

Summary The objectives of this study were to determine the effects of an increased jugular supply of L-Gln on post-weaning growth, immune responses, intestinal morphology and autophagy of weaned calves. At 35 days of age, 24 Holstein calves (initial 50 ± 1.5 kg; 35 ± 2 day of age) were randomly allocated to four treatments, and each treatment included five male and one female calves. Holstein calves were assigned to treatments of (i) i.v. infusion of 2 l of 0.85% NaCl, Control group [C]; (ii) i.v. infusion of 8 g/day of L-Gln mixed with 2 l of 0.85% NaCl solution [L]; (iii) i.v. infusion of 16 g/day of L-Gln mixed with 2 l of 0.85% NaCl solution [M]; and (iv) i.v. infusion of 32 g/day of L-Gln mixed with 2 l of 0.85% NaCl [H]; The infusion was 2 h/day for each of 14 consecutive days starting on day 1 after weaning. Feed and water were freely available to all calves. All calves were killed on the 14th day post-weaning for measurements of autophagy of liver cell and intestinal morphology. Gln has no effect on dry matter intake (DMI) and average daily gain (ADG). Gln infusion increased quadratically the abundance of CD4+, monocyte and the ratio of CD4+/CD8+. The urea N, Gln and Glucose in plasma increased linearly with increasing Gln loads. Gln infusion increased quadratically villus height and crypt depth of intestine. The autophagy level of liver cell was improved with the Gln infusion dose increased.

The enantioselective Henry reaction between nitromethane and various aldehydes catalyzed by chiral amino alcohol–Zn complex was described. The resulting β-nitroalcohols were obtained in high yields and with moderate to good enantiomeric excesses.

The method can be applied to aromatic, aliphatic, and α,β-unsaturated aldehydes to give the corresponding propargylic alcohols.

Summary This study was designed to evaluate the effect of heat stress on endotoxin flux across mesenteric-drained and portal-drained viscera of dairy goats. Three Saanen first lactation dairy goats were surgically fitted with indwelling catheters in the portal vein, the mesenteric vein and carotid, and were kept in thermal-neutral and then heat stress environment, for examining the effect of heat stress on endotoxin absorption and redox status. Average net absorption of endotoxin (EU/h) across mesenteric-drained viscera (MDV) and portal-drained viscera (PDV) during the whole period of heat stress increased by 279.05% and 227.92% in relation to thermo-neutral period. Plasma concentration of glutathione peroxidase (GSH-Px) and catalase (CAT) in mesenteric and portal vein, and that of superoxide dismutase (SOD) in mesenteric vein, increased significantly during heat stress. Main conclusions were: (i) net absorption of endotoxin in portal vein is mainly from non-mesenteric tissues both in heat stress and in thermo-neutral condition; (ii) heat stress may lead to the significant decrease in plasma SOD, GSH-Px, CAT flux across PDV and MDV, and the significant increase in endotoxin flux across PDV and MDV; and (iii) the increase in gastrointestinal permeability in dairy goats during heat stress may not be induced by the increase in oxidative stress.

The racemic mixtures (I) are synthesized and each enantiomer thereof are isolated and structurally characterized.

The synthetic value of the present method is demonstrated by preparation of marine allynols (X).

Asymmetric catalysis: A highly enantioselective and efficient procedure for the amino alcohol-zinc-catalyzed addition of 1,3-diynes to various aromatic, α,β-unsaturated, and aliphatic aldehydes has been developed. The present catalytic system was successfully applied in the concise synthesis of natural products such as (S)-strongylodiols A and B (see scheme).

Aromatic as well as aliphatic aldehydes undergo the Henry reaction with nitromethane under catalysis of an in situ generated chiral amino alcohol—Zn complex to give the corresponding β-nitroalcohols in moderate to good enantioselectivity.

The method can be applied to aromatic, aliphatic, and α,β-unsaturated aldehydes to give the corresponding propargylic alcohols.