Configure OAuthAuthorizationServerProvider via Autofac 4.0

I must integrate Oauth with Autofac. But something goes wrong. I think I understand why, but I don't know how to solve it. I let you see my code.

My Autofac Config

{
    builder.RegisterType<CustomAuthorizationServerProvider>()
            .PropertiesAutowired()
            .SingleInstance();

    builder.RegisterType<MyBusinessObj>()
           .As<IMyBusinessObj>()
           .InstancePerRequest()
           .PropertiesAutowired();

    //IMySessionObj is a prop inside MyBusinessObj
    builder.RegisterType<MySessionObj>()
           .As<IMySessionObj>()
           .InstancePerRequest()
           .PropertiesAutowired();

    //IMyUnitOfWorkObjis a prop inside MyBusinessObj
    builder.RegisterType<MyUnitOfWorkObj>()
           .As<IMyUnitOfWorkObj>()
           .InstancePerRequest();

    ...
}

Startup.cs

I have the classic configuration plus the resolution of my authorizationServerProvider.. As you can see, I resolve it in the container... because it is a singleton.

app.UseAutofacMiddleware(_container);
app.UseAutofacWebApi(config);

var oauthServerOptions = new OAuthAuthorizationServerOptions
{
    ...,
    Provider = _container.Resolve<CustomAuthorizationServerProvider>()
};

app.UseOAuthAuthorizationServer(oauthServerOptions);

app.UseWebApi(config);

CustomAuthorizationServerProvider.cs

This is how I have implemented my CustomAuthorizationServerProvider.

public class CustomAuthorizationServerProvider: OAuthAuthorizationServerProvider
{
    public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
    {
        var autofacLifetimeScope = OwinContextExtensions.GetAutofacLifetimeScope(context.OwinContext);
        var myBusinessObj = autofacLifetimeScope.Resolve<IMyBusinessObj>();
        var xxx = myBusinessObj.DoWork();
        ...
        return Task.FromResult<object>(null);
    }

    public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
    {
        var myBusinessObj = autofacLifetimeScope.Resolve<IMyBusinessObj>();
        var xxx = myBusinessObj.DoWork();
        ...
        context.Validated(ticket);
    }
}

Here I solve my IMyBusinessObj in a lifetimescope, not in the container. This object is responsible (indirectly) to connect to db, access the session, access the cache and so on... so it cannot be a singleton.

I need it would have a lifetime per request. So here the problems.. Two problems there are in my configuration.

1. I have a InstancePerRequest object inside a SingleInstance object. I cannot do that. Troubleshooting Per-Request Dependencies

2. I effectively cannot have a InstancePerRequest object when I configure oauth in the startup... because in that context does not exist a request yet.

So.. I have understood which are my problems.

Any idea or tips? Thank you