How to munge Backbone.Model data before sync

data-munge-sync.coffee

class MyModel extends Backbone.Model
  sync: (method, model, options) =>
    console.log 'MyModel : info : trying to coerce property_X to be property_Y when pushed to server'
    if method in ['create', 'update', 'patch']
      options.attrs = @toJSON(options)
      options.attrs.property_Y = @get('property_X')
      delete options.attrs.property_X
    super