118629-69-9Relevant academic research and scientific papers
Stereospecific synthesis of functionalized ether phospholipids
Kazi, Abul B.,Shidmand, Sean,Hajdu, Joseph
, p. 9337 - 9347 (2007/10/03)
A new stereospecific synthesis of functionalized alkyl ether phospholipids is reported. The synthesis is based upon the following: (1) the use of (R)-glycidyl tosylate as a chiral glycerol precursor; (2) the opening of a boron trifluoride catalyzed epoxide ring to introduce the functionalized sn-1-alkyl substituents; (3) the role of tetrahydropyranyl in protecting the sn-2-glycerol position; and (4) the elaboration of the sn-3-carbinol function, via the base hydrolysis of the acetoxy intermediate, obtained from the displacement of the toluenesulfonyl group of the substrate in dipolar aprotic media. Phosphorylation, using two different methods, has led to the development of two major classes of alkyllysophospholipids. For preparation of 'modulator-phospholipid' analogues, the substituted glycerol is coupled with 2,2,2-trichloro-tert-butyl phosphodichloridite and an N-protected amino acid ester, while elaboration of the phosphocholine headgroup of the target platelet-activating factor (PAF) analogues is achieved via the 2-chloro-2- oxo-1,3,2-dioxaphospholane/trimethylamine sequence. The synthesis provides rapid and efficient access to both types of phospholipids: (1) construction of the functionalized/substituted glycerol skeleton is achieved in a straightforward four-step sequence in better than 50% overall yield, and (2) phosphitylation or phosphorylation of the respective glycerol intermediates relies on reagents that require minimal use of protecting groups. The phospholipid compounds prepared include (1) the first synthetic analogue exhibiting modulator activity in conjunction with the glucocorticoid-receptor complex and (2) an sn-1-(ωamino)alkyl derivative of PAF, suitable for introduction of chain-terminal spectroscopic labels for biological and physicochemical studies to elucidate the mechanism of action of this highly potent alkyl ether phospholipid. The synthetic methods described herein have a great deal of flexibility, thus providing convenient general routes to a wide range of alkyl ether phospholipids.
Arenesulfonate Derivatives of Homochiral Glycidol: Versatile Chiral Building Blocks for Organic Synthesis
Klunder, Janice M.,Onami, Tetsuo,Sharpless, K. Barry
, p. 1295 - 1304 (2007/10/02)
The preparation of a series of crystalline arenesulfonate derivatives of enantiomerically enriched glycidol is described.The enhancement of optical purity by recrystallization was particularly successful for two of these derivatives, glycidyl tosylate and glycidyl 3-nitrobenzenesulfonate, which were obtained in 97 percent ee and 99 percent ee, respectively.Very high regioselectivity was observed in the reactions of these compounds with a variety of nucleophiles, including aryl oxides, Et2AlCN, organometallic reagents, and BH3-NaBH4.The application of this methodology to the synthesis of homochiral β-adrenergic blocking agents and homochiral terminal epoxides is discussed.
