A process for the preparation of a polyunsaturated thiol comprising:
(1) reacting a polyunsaturated alcohol in the presence of a compound of formula R2—SO2Hal wherein R2 is a C1-20 hydrocarbyl group, such an C1-10 alkyl group, to form a polyunsaturated sulphonyl ester;
(2) converting the polyunsaturated sulphonyl ester to a polyunsaturated thioester by reacting with an anion of formula −SC(═O)R4 wherein R4 is a C1-20 hydrocarbyl group;
(3) converting the polyunsaturated thioester to form a polyunsaturated thiol optionally in the presence of an antioxidant, e.g. using a metal carbonate.
(4) reacting said polyunsaturated thiol with a compound (LG)R3COX wherein X is an electron withdrawing group and R3 is an alkylene group carrying a leaving group (LG), such as LG-CH2— forming
where X is an electron withdrawing group and LG is a leaving group; optionally in the presence of an antioxidant, so as to form a polyunsaturated ketone compound.
一种制备多不饱和
硫醇的工艺,包括
(1) 在式 R2-SO2Hal 的化合物(其中 R2 为 C1-20 烃基,如 C1-10 烷基)存在下,使多不饱和醇反应生成多不饱和磺酰酯;
(2) 通过与式-SC(═O)R4(其中 R4 为 C1-20 碳氢基)的阴离子反应,将多不饱和磺酰酯转化为多不饱和
硫酯;
(3) 将多不饱和
硫酯转化为多不饱和
硫醇,可选择在有
抗氧化剂存在的情况下进行,例如使用
金属
碳酸盐。
(4) 将所述多不饱和
硫醇与化合物 (LG)R3COX 反应,其中 X 为取电子基团,R3 为携带离去基团 (LG) 的亚烷基,如 LG-
CH2-,从而形成
其中 X 是取电子基团,LG 是离去基团;可选择在有
抗氧化剂存在的情况下,形成多不饱和酮化合物。