The synthesis of angularly fused quinone natural product G-2N has been achieved using a photoenolization reaction and a Diels-Alder reaction in the key carbon-carbon bond forming steps. This route is direct and flexible. It should be applicable to synthesis of other analogous natural products;The skeleton of colchicine has been achieved using a Diels-Alder reaction followed by an electrophilic addition to the A ring as key steps. Our synthetic approach is direct. It could provide an efficient entry to total synthesis of colchicine.