US 11,746,078 B2
Kinetic resolution reaction of a (1RS,2SR)-(2-hydroxy-3,5,5-trimethyl-3-cyclopentenyl)methyl carboxylate compound, a process for preparing optically active trans-α-necrodyl isobutyrate, and a process for preparing optically active γ-necrodyl isobutyrate
Tomohiro Watanabe, Joetsu (JP); Takeshi Kinsho, Joetsu (JP); Takeru Watanabe, Joetsu (JP); Miyoshi Yamashita, Joetsu (JP); and Yusuke Nagae, Joetsu (JP)
Assigned to Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed by Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed on Jan. 21, 2022, as Appl. No. 17/580,874.
Claims priority of application No. 2021-010360 (JP), filed on Jan. 26, 2021.
Prior Publication US 2022/0234983 A1, Jul. 28, 2022
Int. Cl. C07C 67/08 (2006.01)
CPC C07C 67/08 (2013.01) [C07C 2601/10 (2017.05)] 5 Claims
 
1. A process for preparing a (1S,2R)-(2-hydroxy-3,5,5-trimethyl-3-cyclopentenyl)methyl carboxylate compound of the following general formula (S,R)-(2):

OG Complex Work Unit Chemistry
wherein R1 represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, and
a bold wedged bond represents the absolute configuration, and
a (1R,2S)-(2-acetoxy-3,5,5-trimethyl-3-cyclopentenyl)methyl carboxylate compound of the following general formula (R,S)-(3):

OG Complex Work Unit Chemistry
wherein R1 is as defined above, a hashed wedged bond represents the absolute configuration, and Ac represents an acetyl group,
the process comprising:
subjecting a (1RS,2SR)-(2-hydroxy-3,5,5-trimethyl-3-cyclopentenyl)methyl carboxylate compound of the following general formula (RS,SR)-(2):

OG Complex Work Unit Chemistry
wherein R1 is as defined above, and a hashed unwedged bond represents a relative configuration,
to a kinetic resolution reaction with a lipase in the presence of vinyl acetate to obtain the (1S,2R)-(2-hydroxy-3,5,5-trimethyl-3-cyclopentenyl)methyl carboxylate compound ((S,R)-(2)) and the (1R,2S)-(2-acetoxy-3,5,5-trimethyl-3-cyclopentenyl)methyl carboxylate compound ((R,S)-(3)).