Abstract: A guanidine compound having a biaryl skeleton represented by the following formula (1), which is useful as a catalyst for various asymmetric reactions.

Abstract: The present invention provides an industrially advantageous production method of optically active tetrahydroquinolines of formula (1), which comprises: 1) a step of reacting a ?-ketoester of formula (2) with an amine of formula (3) to produce an enaminoester of formula (4); 2) a step of subjecting the enaminoester of formula (4) above obtained in 1) to asymmetric hydrogenation to produce an optically active ?-amino acid derivative of formula (5); 3) a step of amidating the optically active ?-amino acid derivative (5) above obtained in 2) to produce an amide of formula (6); 4) a step of alkoxycarbonylating the amide of formula (6) above obtained in 3) to produce a compound of formula (7); and 5) a step of subjecting the compound of formula (7) above to cyclization to produce the optically active tetrahydroquinoline of formula (1).

Abstract: An (E)-(R)-2-alkyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)-2-buten-1-ol represented by formula (I): wherein R represents an alkyl group having 1 to 3 carbon atoms,and a process for preparing the same comprising hydrogenating a corresponding (E)-(R)-2-alkyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)-2-buten-1-al in the presence of a ruthenium-phosphine complex as a catalyst, a base comprising an alkali metal or an alkaline earth metal, and an amine. The compound (I) has an excellent sandalwood oil odor.