If by "dissolved" you are saying that the company liquidated itself and you received some of the liquidating distributions, then those amounts are your "proceeds" from the sale of the stock and you'd enter this sale using the "Stocks, Mutual Funds, Bonds, Other" interview. You would tell TurboTax that you didn't get a 1099-B reporting the sale and TurboTax will place the information in the proper section of Form 8949/
If you are saying that the stock is completely worthless and no proceeds were received, you still report this as a form of "sale" using the "Stocks, Mutual Funds, Bonds, Other" interview, again telling TurboTax that no Form 1099-B was received. Enter a description like "Worthless (Company X) stock", a "proceeds" of $0 and a "sale date" of 12/31/15.
The IRS has strict rules about what constitutes a worthless stock and just being in bankruptcy probably is not sufficient
Tom Young
