Legal Question in Business Law in California

A shareholder is entitled to his share of the business in a sale or dissolution. If he does as threatened, you would have grounds to sue for various causes of action including breach of good faith and 'fraud'. However, your best option is to negotiate a proper resolution of your interest, even if that means hiring an attorney to exert 'pressure' on the company to do it right, on the threat of lawsuit if they don't. If serious about hiring counsel for this, feel free to contact me.

A majority shareholder has "fiduciary obligations" of care and loyalty to a minority shareholder. Breach of those obligations will give the minority shareholder a right to sue the majority shareholder.

You need to get a lawyer to help you plan a strategy here to protect your interests. A majority shareholder may well be in breach of his obligations to a minority shareholder by acting in the way you suggest.

It is not even slightly legal. Even if he did that, you could sue him for stealing the customer information and other valuable trade information and intellectual property of the dissolved corporation.