Nested Json Marshalling in Go coding

Question

Being new to a Go, I am bit unsure how to perform a object creation in Go for Json Marshalling. I have a structure that I want to create var object out of it.

type myStruct struct {
    A struct {
        B struct {
            C bool `json: "c", omitempty`
        }
    }
}

type a struct {
   B b `json:"b"`
}

type b struct {
    C bool `json:"c",omitempty`
}

and the corresponding instant I wanted to create is this

var myStructVar = myStruct {
    a{
        b{
            C: valC, // valC is a constant in my case
        },
    },
}

But when I execute this it gives me error

cannot use a{…} (value of type a) as type struct ..... in struct literal