18452-41-0Relevant academic research and scientific papers
Enantiospecific total synthesis of both enantiomers of laurene by a chemical diastereoselection/lipase-catalyzed kinetic resolution sequence
Laval, Gilles,Audran, Gerard,Sanchez, Sylvie,Monti, Honore
, p. 1927 - 1933 (2007/10/03)
A short and efficient enantiospecific total synthesis of natural (+)- laurene and its enantiomer is described. The methodology was developed by employing a stereoselective H-ene reaction of an isocyclic allyltrimethylsilane with paraformaldehyde, followed by a lipase-mediated kinetic resolution of the racemic key intermediate.
Conformational control in the cyclization of an unsaturated vinyllithium: Synthesis of (±)-laurene
Bailey,Jiang,McLeod
, p. 7791 - 7795 (2007/10/03)
The olefinic vinyllithium 2, derived from 2-bromo-5-methyl-5-(4-methylphenyl)-1,6-heptadiene (3) by low-temperature lithium-bromine exchange, undergoes a diastereoselective 5-exo cyclization at 0°C in the presence of TMEDA to afford the naturally occurring sesquiterpene (±)-laurene (1) in 60% isolated yield along with 17% of the isomeric (±)-epilaurene (4). The diastereoselectivity of the cyclization of 2 is discussed in terms of a transition state for the process that approximates a chair cyclohexane which preferentially adopts a conformation having a pseudoaxial p-tolyl moiety and a pseudoequatorial methyl group at the geminally substituted carbon. In contrast to the behavior of 2, radical-mediated cyclization of 3 proceeds entirely in a 6-endo fashion to give 4-methyl4-(4-methylphenyl)-1-methylenecyclohexane (6) in 93% yield.
Synthesis of Vicinal Stereogenic Tertiary and Quaternary Centers Using Chiral Bicyclic Lactams and Diastereoselective Protonation. Asymmetric Synthesis of (+)-Laurene
Schwarz, Jacob B.,Meyers, A. I.
, p. 6511 - 6514 (2007/10/03)
The chiral bicyclic lactam 5, previously reported in the synthesis of (-)-α-cuparenone, was used to construct the more complex title compound 2.A mixture of cyclopentenones 8 and 9 was subjected to deprotonation/reprotonation to provide 8 in high diastereomeric excess.Transformation of 8 to the title compound was achieved by catalytic hydrogenation to 13, followed by methylenation with the Tebbe reagent.
Chiral Cyclobutanones as Versatile Synthons: the First Enantioselective Total Synthesis of (+)-Laurene
Nemoto, Hideo,Nagamochi, Masatoshi,Fukumoto, Keiichiro
, p. 2329 - 2332 (2007/10/02)
A novel and convenient route to the thermodynamically unstable ketone 11 via the cyclopentanone 8 which was synthesised by palladium-mediated ring expansion of the chiral siloxyvinylcyclobutanes 9 and 10 has been developed.This leads to an enantioselectiv
The First Enantioselective Total Synthesis of (+)-Laurene
Nemoto, Hideo,Nagamochi, Masatoshi,Fukumoto, Keiichiro
, p. 1695 - 1697 (2007/10/02)
The cyclopentenone 8, synthesized by palladium mediated ring expansion of the chiral vinylcyclobutanols 3 and 4, is converted to the thermodynamically unstable ketone 16 which on methylenation gives (+)-laurene 1.
TOTAL SYNTHESIS OF (+/-)-LAURENE AND EPILAURENE BY RADICAL CYCLISATION REACTION
Srikrishna, A.,Sunderbabu, G.
, p. 3561 - 3562 (2007/10/02)
Total synthesis of (+/-)-laurene and epilaurene, via the radical cyclisation of the xanthate (11) derived from the acetylenic alcohol (10), is described.
Six New Sesquiterpenoids from the Red Alga Laurencia nipponica Yamada
Suzuki, Teruaki,Kikuchi, Hajime,Kurosawa, Etsuro
, p. 1561 - 1563 (2007/10/02)
Six new laurane-type sesquiterpenoids were isolated from the red alga Laurencia nipponica Yamada and their structures were established on the basis od spectral and chemical evidence.
Stereoselective synthesis of (±) - laurene
Taber, Douglass F.,Anthony, James Michael
, p. 2779 - 2782 (2007/10/02)
Reduction of an unsymmetrically substituted unsaturated aldehyde by way of the corresponding tosylhydrazone is shown to proceed stereoselectively.
