General Strategy for the Synthesis of B<sub>1</sub> Phytoprostanes, Dinor Isoprostanes, and Analogs
作者:Annika Schmidt、Wilhelm Boland
DOI:10.1021/jo062359x
日期:2007.3.1
The synthesis of the phytoprostane B1 types I and II is achieved in high overall yield (35−53%) by only two principal transformations starting from 1,3-cyclopentanedione. The first side chain is attached via O-acylation of the 1,3-dione followed by rearrangement and reduction to give the 2-alkyl-1,3-diones 4a−c. After conversion into the corresponding vinylic iodides 5a−c, the second side chain is
Synthesis of Farnesol Analogues through Cu(I)-Mediated Displacements of Allylic THP Ethers by Grignard Reagents
作者:Mark F. Mechelke、David F. Wiemer
DOI:10.1021/jo990161p
日期:1999.6.1
The synthesis of a family of farnesol analogues, incorporating aromatic rings, has been achieved in high yields through the development of a regioselective coupling of allylic tetrahydropyranyl ethers with organometallic reagents. The allylic THP group is displaced readily by Grignardreagents in the presence of Cu(I) halides but is stable in the absence of added copper. Thus, an allylic THP group
Silica chloride in the presence of NaI is a useful system for the efficient and selective conversion of TMS, TBDMS and THP ethers into their corresponding iodides
Direct and highly selective conversion of benzylic, allylic and propargylic TMS, TBDMS and THP ethers into their corresponding iodides with the SiO2–Cl/NaI system is described. Reactions were conducted in CH3CN at room temperature. Aliphatic silyl and tetrahydropyranyl ethers remained almost intact under similar reaction conditions.
Selective removal of tetrahydropyranyl ethers in the presence of tert-butyldimethylsilyl ethers with magnesium bromide in ether
作者:Sunggak Kim、Jung Ho Park
DOI:10.1016/s0040-4039(00)95749-6
日期:1987.1
It has been found that tetrahydropyranyl ethers are cleanly and selectively deprotected in the presence of tert-butyldimethylsilyl ethers with magnesium bromide in ether.
3-(Optionally oxygenated)-5-oxocyclopent-1-enealkanoic acids and their alkyl esters are allowed to react with appropriate alkenyl copper, alkenyl boron, alkynyl boron, alkynyl gallium or alkynyl aluminum compounds to produce the corresponding 2-(3-hydroxy-3-[optionally alkylated]-1-alkenyl)cyclopentanealkanoic acids, 2-(3-hydroxy-3-[optionally alkylated]-1-alkynyl)cyclopentanealkanoic acids and their esters. The prostaglandin derivatives so produced are valuable and useful as pharmacological agents as is evidenced by their central nervous system-affective, anti-bacterial, anti-fungal and prostaglandin antagonist activity.