Compound A (C4H10) gives two different monochlorides on photochemical chlorination. Treatment of either of these monochlorides with

Question:

Compound A (C4H10) gives two different monochlorides on photochemical chlorination. Treatment of either of these monochlorides with potassium tert-butoxide in dimethyl sulfoxide gives the same alkene B (C4H8) as the only product. What are the structures of compound A, the two monochlorides, and alkene B?