Improved Synthesis and Resolution of α-N-Benzoyl-β(3-Qumolyl)-DL-α-Alanine Methyl Ester

The title compound has been synthesized and resolved previously by T. M. Kubiak. In our searching of new potent agonists of LH-RH(luteinizing hormone releasing hormone), α-N-t-butyloxycarbonyl-β-3-quinolyl)-D-α-alanine and its L-isomer were synthesized. The unprotected.optically active amino acids were obtained by enzymatic hydrolysis of the title compounds, followed by hydrolysis in 6 mol/L hydrochloric acid. The title compound was synthesized initially with 3-quinolinecar-

Improved Synthesis of Miriplatin

Miriplatin, a novel lipophilic platinum complex has been developed to treat hepatocellular carcinoma. An improvd synthetic route was designed and used to prepare the target compound. The intermediate Pt(C6H14N2)(I) 2 was synthesized from K 2 PtCl 4 , KI and (1R,2R)-1,2-cyclohexanediamine, Pt(C 6 H 14 N 2 )(I) 2 was reacted with AgNO 3 to prepare Pt(C 6 H 14 N 2 )(H 2 O) 2 (NO 3 ) 2 solution then was subsequently reacted with CH 3 (CH 2 ) 12 COONa in n-butanol to give target compound with satisfied yield 81%(based on Pt(C 6 H 14 N 2 )I 2 ). The structure of the target compound was identified by elemental analysis, ESI-MS, FT-IR, 1H-NMR, thermal analysis, the structure was consistent with the target compound.

An Improved Synthesis of dl-Muscone

M. Stoll's total synthetic route for dl-muscone was improved. 2.15.Hexadecanedione was synthesized by PTC method and converted into dehydromuscones through intramolecular aldol reaction by the mixture of zinc chloride and the Grinard reagent of isoamyl bromide used as condensing agent. Catalytic hydrogenation of dehydromuscones gave dl-muscone.

STUDIES ON CARBOHYDRATES XII.AN IMPROVED KOENIGS KNORR METHOD FOR HIGHLY STEREOSELECTIVE SYNTHESIS OF 1-O-ACYL-β-D-GALACTOPYRANOSE TETRAACETATES

2,3,4,6-Tetra-O-acetyl-α-D-galactopyranosyl bromide reacted with carboxylic acids in the presence of CaH_2 and Ag_2CO_3 and small amount of I_2 to give good yields of l-O-acyl-β-D- galactopyranose tetraaeetates.β-Anomers of glycosyl esters were obtained by this improved Koenigs-Knorr method.

A genetic diversity assessment of starch quality traits in rice landraces from the Taihu basin,China

There are nearly 1 000 rice landrace varieties in the Taihu basin, China. To assess the genetic diversity of the rice, 24 intragenic molecular markers（representing 17 starch synthesis-related genes） were investigated in 115 Taihu basin rice landraces and 87 improved cultivars simultaneously. The results show that the average genetic diversity and polymorphism information content values of the landraces were higher than those of improved cultivars. In total, 41 and 39 allele combinations（of the 17 genes） were derived from the landraces and improved cultivars, respectively; only two identical allele combinations were found bet ween the two rice variety sources. Cluster analysis, based on the molecular markers, revealed that the rice varieties could be subdivided into five groups and, within these, the japonica improved rice and japonica landrace rice varieties were in two separate groups. According to the quality reference criteria to classify the rice into grades, some of the landraces were found to perform we ll, in terms of starch quality. For example, according to NY /T595-2002 criteria from the Ministry of Agriculture of China, 25 and 33 landraces reached grade 1, in terms of their apparent amylose content and gel consistency. Th e varieties that had outstanding quality could be used as breeding materials for rice quality breeding programs in the future. Our study is useful for future applications, such as genetic diversity studies, the protection of rice variety and improvment of rice quality in breeding programs.

Improved synthesis of key intermediate of grayanotoxin Ⅲ

A concise improved synthesis of the key intermediate for the synthesis of grayanotoxinⅢwas realized in the present study,featuring a tandem reaction of Michael addition-esterification,Mukaiyama hydration and Mukaiyama dehydrogenaiton.