Preparation of enantiomerically enriched compound using enzymes. Part 3. Enzymic preparation of enantiomerically enriched tertiary .alpha.-benzyloxy acid esters. Application to the synthesis of (S)-(-)-frontalin
A series of novelacyclic thymine nucleoside analogues were prepared by the Mitsunobu reaction from appropriately protected chiral triols. The enantiomeric triols were obtained from substituted γ-lactone acids, prepared by asymmetric oxidation of 3-substituted-1,2-cyclopentanediones. The cytotoxic activity of new analogues was evaluated on MCF-7 human breast cancer and HeLa cells, and antiviral activities
Pectenotoxin-2 Synthetic Studies. 2. Construction and Conjoining of ABC and DE Eastern Hemisphere Subtargets
作者:Dmitriy Bondar、Jian Liu、Thomas Müller、Leo A. Paquette
DOI:10.1021/ol0504291
日期:2005.4.1
[reaction: see text] Practical asymmetric synthesis of aldehyde 2 and tetrazolyl sulfone3 has allowed for their coupling via Julia olefination to generate 32 as a single product. This substance possesses the entire carbon backbone of the A-E substructure of pectenotoxin-2.
New Farnesane-Type Sesquiterpenes, Hedychiols A and B 8,9-Diacetate, and Inhibitors of Degranulation in RBL-2H3 Cells from the Rhizome of Hedychium coronarium.
Two new farnesane-type sesquiterpenes, hedychiols A and B 8,9-diacetate, were isolated from the methanolic extract of the fresh rhizome of Hedychium coronarium KOEN. cultivated in Japan. Their stereostructures were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of isolated constituents on the release of β-hexosaminidase from RBL-2H3 cells were examined, and hedychilactone A and coronarin D were found to show the inhibitory activity.
(R)-(+)-Frontalin (1) and its antipode (1′) were synthesized from (R)-(+)-2-hydroxy-2-methylpentane-1,5-dioic acid 5→2 lactone (2) and its antipode (2′), respectively. This established the absolute configurations of both enantiomers of frontalin and afforded key materials to study the relationship between pheromone activity and chirality.
Preparation of Optically Active Tertiary Alcohols by Enzymatic Methods. Application to the Synthesis of Drugs and Natural Products
作者:Same-Ting Chen、Jim-Min Fang
DOI:10.1021/jo970236u
日期:1997.6.1
enantioselectivities (E >/= 153). The obtained enantiomerically pure or optically enriched compounds, containing an iodo atom, an oxirane moiety, or an alkynyl group, are versatile building blocks for the synthesis of chiral azido diols, sulfanyl diols, cyano diols, the side chain of a vitamin D(3) metabolite, the omega-chain of a prostaglandin analog, and an aggregation pheromone (1S,5R)-(-)-frontalin. Models