US 11,958,797 B2
Process for the preparation of intermediates for the synthesis of vitamin A derivatives from polyenes by cyclisation
Fabrice Aquino, Kaiseraugst (CH); Werner Bonrath, Kaiseraugst (CH); Marc-André Mueller, Kaiseraugst (CH); and Bettina Wuestenberg, Kaiseraugst (CH)
Assigned to DSM IP ASSETS B.V., Heerlen (NL)
Appl. No. 17/603,177
Filed by DSM IP ASSETS B.V., Heerlen (NL)
PCT Filed Apr. 3, 2020, PCT No. PCT/EP2020/059481
§ 371(c)(1), (2) Date Oct. 12, 2021,
PCT Pub. No. WO2020/212165, PCT Pub. Date Oct. 22, 2020.
Claims priority of application No. 19169204 (EP), filed on Apr. 15, 2019.
Prior Publication US 2022/0204434 A1, Jun. 30, 2022
Int. Cl. C07C 49/21 (2006.01); C07C 45/67 (2006.01)
CPC C07C 49/21 (2013.01) [C07C 45/67 (2013.01); C07C 2601/16 (2017.05)] 14 Claims
 
1. Process for the production of a compound of formula (II)

OG Complex Work Unit Chemistry
by cyclisation of a compound of formula (I)

OG Complex Work Unit Chemistry
in the presence of at least one strong Brønsted acid.