Lewis Base Catalyzed, Sulfenium Ion Initiated Enantioselective, Spiroketalization Cascade
作者:Kimberly M. Hilby、Scott E. Denmark
DOI:10.1021/acs.joc.1c02271
日期:2021.11.5
A Lewisbasecatalyzed, enantioselective sulfenocyclization of alkenes to afford [6,6]spiroketals has been developed. The method uses a chiralLewisbase catalyst with an electrophilic sulfur source to generate enantioenriched thiiranium ion with alkenes. Upon formation, the thiiranium ion is subsequently captured in a cascade-type reaction, wherein a ketone oxygen serves as the nucleophile to open
Synthesis of cholesterol analogs having varying length alkyl side chains including cholesterol-23, 23, 24, 24, 25, 26, 26, 26, 27, 27, 27-d11 as probes of cholesterol's functions and properties
作者:Dong Jae Baek、Robert Bittman
DOI:10.1016/j.chemphyslip.2013.08.003
日期:2013.10
long-chain analogs of cholesterol were prepared by alkylation of cyano-containing sterols with isopentyl-d11 4-methylbenzenesulfonate (1.0 equiv.) or with isoalkyl bromides, followed by reductivedecyanation with excess potassium metal and a crown ether in toluene. The products are potentially useful probes of the role of the side-chain of cholesterol in the sterol's interactions with membrane lipids and proteins
Novel substituted piperidines of the general formulae (I) and (II)
with the substituent definitions as explained in detail in the description are described. The compounds are suitable in particular as renin inhibitors and are highly potent.