2-2 invasion behind sansan

[Phobos]

$$B
$$ -----------------------------
$$ - . . . . . . .
$$ - . 2 . . . . .
$$ - . 3 1 . . . .
$$ - . 4 . . . . .
$$ - . . . . . . .
$$ - . . . . . . .
$$ - . . . . . . .
$$ - . . . . . . .

Click Here To Show Diagram Code

[go]$$B
$$ -----------------------------
$$ - . . . . . . .
$$ - . 2 . . . . .
$$ - . 3 1 . . . .
$$ - . 4 . . . . .
$$ - . . . . . . .
$$ - . . . . . . .
$$ - . . . . . . .
$$ - . . . . . . .[/go]

I don't find this sequence in Kogo's Joseki Dictionary.
White in corner is dead but what is the best response for black to ? And why?
Thank you.
Have a nice day.

[Gomoto]

3 is a big mistake, ELF suggests:

[EdLee]

Hi Phobos,

Nice to try Leela's options for ,
but the game is not decided here.
Example:

$$B
$$ ---------------
$$ | . . . . . . .
$$ | . 2 . . . . .
$$ | . 3 1 . . . .
$$ | . 4 5 . . . .
$$ | . 6 7 . . . .
$$ | . . . . . . .
$$ | . . . . . . .

Click Here To Show Diagram Code

[go]$$B
$$ ---------------
$$ | . . . . . . .
$$ | . 2 . . . . .
$$ | . 3 1 . . . .
$$ | . 4 5 . . . .
$$ | . 6 7 . . . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]

Depends on the whole board situation.

[Uberdude]

Psychologically, I want to tenuki the 2-2 just to show my opponent how silly I think he is being (as a general principle when your opponent plays a weird move tenuki is rarely worse than the wrong answer). If white follows up by continuing with the 2-2 it looks bad for him, probably one space approach trying to get passive block is better. Answering more efficiently like Gomoto showed should also suitably embarrass white.