Nobody bid this Slam which is hardly surprising as it is difficult to show the shape and strength.

One way you might get there is if East bids 3♠ immediately after West opens 1♦ . 1♠ and 2♠ show Spade suits of different strengths.

3♠ over 1♥ would be a Splinter showing 4-card support and a void or singleton Spade. Over a 1♣ or 1♦ opening I prefer a double-jump to be a Cue-Bid showing first round Control.

So 1♦ - 3♠ says I have four Diamonds and the ♠ A (or void), 4♥ now says I have the ♥ A but not the ♣ A.

East isn't bothered about the lack of a Club Ace and can now bid 6♦.