Synthesis of the enantiomers of lasiol, an acyclic monoterpene alcohol in the mandibular gland secretion of the male ants, Lasius meridionalis.
(2S,3S)-(-)-Lasiol (2,3,6-trimethyl-5-hepten-1-ol, 1) and its antipode were synthesized from cis-4,5-dimethylcyclohexene oxide (3) by employing asymmetric cleavage of the epoxy ring with a chiral lithium amide derived from 4 to give optically active cis-4,5-dimethyl-2-cyclohexen-1-ol (5) as the key-step.
Lithium diisopinocampheylamide: a new and highly effective chiral catalyst in the enantioselective deprotonation of meso-epoxides
Abstract α-Pinene based novel chiral lithium amides have been used for the catalytic enantioselective deprotonation of cyclohexene oxide. An enantiomeric excess of up to 95% for ( R )-2-scyclohexen-1-ol was achieved with lithium (−)- N , N -diisopinocampheylamide. A systematic study shows that the isopinocampheyl moiety plays an important role in achieving high enantioselectivity.
One-pot synthesis of annulated pyrido[2,3-d:6,5-d]dipyrimidine derivatives using nitrogen based DBU catalyst in aqueous ethanol medium
Abstract We have reported DBU as an efficient organocatalyst for one-pot three-component synthesis of annulated pyrido[2,3- d :6,5- d ]dipyrimidine derivatives using aromatic aldehyde, thio-barbituric acid and 6-amino-uracil in aqueous ethanol under reflux. The attractive advantages of this process are mild reaction conditions, environment friendly procedure, short reaction times, easy isolation of products, and excellent yields (72–89%).