US 12,410,117 B2
Process for production of vitamin A
Werner Bonrath, Kaiseraugst (CH); Marc-André Mueller, Kaiseraugst (CH); Bettina Wuestenberg, Kaiseraugst (CH); and Viktor Zimmermann, Kaiseraugst (CH)
Assigned to DSM IP ASSETS B.V., Heerlen (NL)
Appl. No. 17/915,453
Filed by DSM IP ASSETS B.V., Heerlen (NL)
PCT Filed Mar. 22, 2021, PCT No. PCT/EP2021/057243
§ 371(c)(1), (2) Date Sep. 28, 2022,
PCT Pub. No. WO2021/197890, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 20167019 (EP), filed on Mar. 31, 2020.
Prior Publication US 2023/0125156 A1, Apr. 27, 2023
Int. Cl. C07C 67/08 (2006.01); C07C 69/28 (2006.01)
CPC C07C 67/08 (2013.01) [C07C 69/28 (2013.01); C07C 2601/16 (2017.05)] 15 Claims
 
1. A process for the production of the compound of formula (III)

OG Complex Work Unit Chemistry
wherein R is H or —(CO)—(CH2)nCH3, wherein n has a value of 0-14, or
R is —X(C1-4alkyl)3 or —X(C6H5)3, wherein X is Si or Ge, or
R is tetrahydro pyrane, isopropylmethyl ether or 2-methoxy-butylether, wherein the process comprises:
(i) conducting a first step of treating a compound of formula (I):

OG Complex Work Unit Chemistry
with heat to form a compound of formula (II):

OG Complex Work Unit Chemistry
wherein R in the formulas (I) and (II) has the same meaning as defined for the compound of formula (III), and then
(II) conducting an elimination reaction in a second step to convert the compound of formula (II) into the compound of formula (III).