How do I implement "normal" ES5 prototypal inheritance in React?

I am under the impression that ES6 classes are basically syntactic sugar around the ES5 object system. Since I'm trying to run React without a transpiler, I figured I can only use the old syntax to define "classes" objects that "inherit" from React.Component.

    var Board = function(props, state) {
        var instance = {};

        instance.props = props;
        instance.context = state;

        return(instance);           
    };

    Board.prototype = Object.create(React.Component.prototype);

    Board.prototype.render = function() {
        return(
            // ...stuff
        )               
    };

      

        
        
        
      

    

But it doesn't work!

react.js:20478 Warning: Board(...): No `render` method found on the returned component instance: you may have forgotten to define `render`
react.js:6690 Uncaught TypeError: inst.render is not a function(…)

      

        
        
        
      

    

I found alternatives in this context and the following works:

    var Board = function(props, state) {
        var instance = Object.create(React.Component.prototype);

        instance.props = props;
        instance.context = state;

        instance.prototype.render = function() {
            return(
                // ...stuff
            )               
        };

        return(instance);           
    };

      

        
        
        
      

    

I also figured out that I can use a helper React.createClass

.

But I would still like to understand why React won't handle classes defined in this general way. It seems to me that ES6 classes are used prior to use. I see no reason why ES5 class classes would also not be driven by similar results.