135356-99-9Relevant academic research and scientific papers
(-)-sparteine-mediated asymmetric intramolecular carbolithiation of alkenes: Synthesis of enantiopure cyclopentanes with three consecutive stereogenic centers
Hoppe, Dieter,Weltering, Michael J.,Oestreich, Martin,Froehlich, Roland
, p. 1860 - 1877 (2007/10/03)
An asymmetric intramolecular carbolithiation reaction was developed by combining the (-)-sparteine-mediated enantiotopos-differentiating deprotonation and the anionic 5-exo-trig cyclization. Achiral 6-phenylhex-5- enyl carbamates were efficiently cyclized furnishing regio-, diastereo- (dr >99:1), and enantioselectively (er >98:2) 1,2-trans-substituted cyclopentanes. The intermediate primary benzylic lithium-carbanion pairs were - in spite of their configurative lability - diastercoselectively substituted by versatile electrophiles creating a third consecutive stereogenic center. Additionally, some 4-functionalized 6-phenylhex-5-enyl carbamates were also cyclized in high yield to provide enantiomerically pure cyclopentanes incorporating three adjacent stereogenic centers.
Enzymatic hydrolysis and esterification. Routes to optically pure cyclopentanols
Seemayer, R.,Schneider, M. P.
, p. 171 - 174 (2007/10/02)
Using an esterhydrolase from Pseudomonas sp. (SAM II), a series of optically pure cyclopentanols 1-4 was prepared by enzymatic hydrolysis of their corresponding acetates.Using the same enzyme, these cyclopentanols were esterified by enol esters as acyl do
