Processes of making γ,δ-unsaturated carboxylic acid and silyl ester thereof, carboxyl group-containing organosilicon compound and process of making

An organosilicon compound having a silylated carboxyl group, represented by the general formula (5):

• wherein R1, R2, R3, R4, R4′, R5, R6 and R6′ are each independently a monovalent C1-C20 hydrocarbon group which may be halo-substituted, a halogen atom, or a hydrogen atom, or a pair of R1 and R2, R1 and R3, R4 and R4′, R4 and R6, R4′ and R6, or R5 and R6′ may bond together to form a ring;
• Ra, Rb and Rc are independently selected from the class consisting of C1-C20 alkyl, C6-C20 aryl, C7-C20 aralkyl, C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups in which a group bonded to a silicon atom is a monovalent C1-C20 hydrocarbon group or hydrogen, substituted forms of the foregoing groups in which a hydrogen atom bonded to a carbon atom is substituted with a halogen atom, and halogen atoms, or a pair of Ra and Rb, Ra and Rc, or Rb and Rc may bond together to form a siloxane ring of 3 to 50 silicon atoms or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are bonded, or Ra, Rb and Rc may bond together to form a cage siloxane of 6 to 50 silicon atoms with the silicon atom to which they are bonded;
• Rd is selected from the class consisting of C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups of 1 to 1,000 silicon atoms in which a group bonded to a silicon atom is a substituted or unsubstituted monovalent C1-C20 hydrocarbon group or hydrogen, and halogen atoms, Re and Rf are independently selected from the class consisting of C1-C20 alkyl, C6-C20 aryl, C7-C20 aralkyl, C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups of 1 to 1,000 silicon atoms in which a group bonded to a silicon atom is a substituted or unsubstituted monovalent C1-C20 hydrocarbon group or hydrogen, and halogen atoms, Rd, Re and Rf may have a substituent group free of unsaturation that undergoes hydrosilylation, or a pair of Rd and Re, Rd and Rf, or Re and Rf may bond together to form a siloxane ring of 3 to 50 silicon atoms or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are bonded, or Rd, Re and Rf may bond together to form a cage siloxane of 6 to 50 silicon atoms with the silicon atom to which they are bonded.

A process of preparing an organosilicon compound having a carboxyl group represented by the general formula (7), comprising the step of desilylating an organosilicon compound having a silylated carboxyl group represented by the general formula (5),

• wherein R1, R2, R3, R4, R4′, R5, R6 and R6′ are each independently a monovalent C1-C20 hydrocarbon group which may be halo-substituted, a halogen atom, or a hydrogen atom, or a pair of R1 and R2, R1 and R3, R4 and R4′, R4 and R6, R4′ and R6, or R5 and R6′ may bond together to form a ring;
• Ra, Rb and Rc are independently selected from the class consisting of C1-C20 alkyl, C6-C20 aryl, C7-C20 aralkyl, C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups in which a group bonded to a silicon atom is a substituted or unsubstituted monovalent C1-C2-0 hydrocarbon group or hydrogen, substituted forms of the foregoing groups in which a hydrogen atom bonded to a carbon atom is substituted with a halogen atom, and halogen atoms, or a pair of Ra and Rb, Ra and Rc, or Rb and Rc may bond together to form a siloxane ring of 3 to 50 silicon atoms or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are bonded, or Ra, Rb and Rc may bond together to form a cage siloxane of 6 to 50 silicon atoms with the silicon atom to which they are bonded;
• Rd is selected from the class consisting of C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups of 1 to 1,000 silicon atoms in which a group bonded to a silicon atom is a substituted or unsubstituted monovalent C1-C20 hydrocarbon group or hydrogen, and halogen atoms, Re and Rf are independently selected from the class consisting of C1-C20 alkyl, C6-C20 aryl, C7-C20 aralkyl, C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups of 1 to 1,000 silicon atoms in which a group bonded to a silicon atom is a substituted or unsubstituted monovalent C1-C20 hydrocarbon group or hydrogen, and halogen atoms, Rd, Re and Rf may have a substituent group free of unsaturation that undergoes hydrosilylation, or a pair of Rd and Re, Rd and Rf, or Re and Rf may bond together to form a siloxane ring of 3 to 50 silicon atoms or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are bonded, or Rd, Re and Rf may bond together to form a cage siloxane of 6 to 50 silicon atoms with the silicon atom to which they are bonded;
• Rg is selected from the class consisting of hydroxyl, C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups of 1 to 1,000 silicon atoms in which a group bonded to a silicon atom is a substituted or unsubstituted monovalent C1-C20 hydrocarbon group or hydrogen, and halogen atoms, Rh and Ri are independently selected from the class consisting of hydroxyl, C1-C20 alkyl, C6-C20 aryl, C7-C20 aralkyl, C1-C20 alkoxy, C6-C20 aryloxy, C7-C20 aralkyloxy, organosiloxy groups of 1 to 1,000 silicon atoms in which a group bonded to a silicon atom is a substituted or unsubstituted monovalent C1-C20 hydrocarbon group or hydrogen, and halogen atoms, Rg, Rh and Ri may have a substituent group free of unsaturation that undergoes hydrosilylation, or a pair of Rg and Rh, Rg and Ri, or Rh and Ri may bond together to form a siloxane ring of 3 to 50 silicon atoms or a silicon-containing ring of 1 to 20 carbon atoms with the silicon atom to which they are bonded, or Rg, Rh and Ri may bond together to form a cage siloxane of 6 to 50 silicon atoms with the silicon atom to which they are bonded.