- Enantioselective synthesis of (-)-CP-55940 via ruthenium-catalyzed asymmetric hydrogenation of ketones
-
A new and efficient catalytic asymmetric synthesis of the potent cannabinoid receptor agonist (-)-CP-55940 has been developed by using ruthenium-catalyzed asymmetric hydrogenation of racemic α-aryl ketones via dynamic kinetic resolution (DKR) as a key step. With RuCl2-SDPs/ diamine [SDPs=7,7'-bis(diarylphophino)-1,1'-spirobiindane] catalysts the asymmetric hydrogenation of racemic α-arylcyclohexanones via DKR provided the corresponding cis-β-arylcyclohexanols in high yields with up to 99.3% ee and >99:1 cis-selectivities. Both ethylene ketal group at the cyclohexane ring and ortho-methoxy group at the phenyl ring of the substrates 6 have little effect on the selectivity and reactivity of the hydrogenations. Based on this highly efficient asymmetric ketone hydrogenation, (-)-CP-55940 was synthesized in 13 steps (the longest linear steps) in 14.6% overall yield starting from commercially available 3-methoxybenzaldehyde and 1,4-cyclohexenedione monoethylene acetal. Copyright
- Cheng, Li-Jie,Xie, Jian-Hua,Wang, Li-Xin,Zhou, Qi-Lin
-
experimental part
p. 1105 - 1113
(2012/05/21)
-
- Expedient synthesis of potent cannabinoid receptor agonist (-)-CP55,940
-
(Chemical Equation Presented) A stereocontrolled synthesis of (-)-CP55,940, a potent cannabinoid receptor agonist, has been attained using a novel aldolization/retroaldolization interconversion strategy, in which a temporarily generated chiral aldol motif plays essential roles.
- Itagaki, Noriaki,Sugahara, Tsutomu,Iwabuchi, Yoshiharu
-
p. 4181 - 4183
(2007/10/03)
-
- 2-Hydroxy-4-(substituted) phenyl cycloalkanes and derivatives
-
Compounds having the formula STR1 R1 is hydrogen, benzyl or an ester moiety; Y is --CH(R2 ")CH(R2)-- or--CH(R3)CH2 --; R2 " is hydrogen or methyl; R2 is OH or X-substituted (C1-6)alkyl; R3 is OH, cyano or X-substituted (C1-3) alkyl; X is --OR6, --SR6, --S(O)R6, --S(O)2 R6, --NR6 R7, --COOR7, --CONR7 R8 or oxo; with the proviso that when X is --NR6 R7, --COOR7 or --CONR7 R8, said group is located on the terminal carbon atom of R2 or R3 ; R6 is hydrogen, (C1-6)alkyl or acetyl; each of R7 and R8 is hydrogen or (C1-6)alkyl; s is an integer of 1 or 2; with the proviso that when R6 is acetyl, R7 is hydrogen and X is other than S(O)R6 or S(O)2 R6 ; Z--W is alkyl, phenylalkyl or pyridylalkyl which can have an oxygen atom as part of the alkyl chain, and their use as CNS agents, antidiarrheals and antiemetics. Processes for their preparation and intermediates therefor are described.
- -
-
-
