SAN FRANCISCO — In a lateral move that can only be compared to an earthquake rocking Silicon Valley’s legal world, Cooley Godward Kronish’s two leading M&A lawyers and the head of its busy tech transactions group are leaving for Dewey & LeBoeuf.

The announcement that rainmakers and longtime Cooley leaders Richard Climan and Keith Flaum, plus tech practice leader Eric Reifschneider, were moving to Dewey’s small East Palo Alto office shocked lawyers all around the Valley.