Tonghaosu 1, a natural product discovered from several plants of tribe Athemdeae, is a [4.4] spiroketal with an enediyne side-chain and shows interesting insect antifeeding activity. In this paper a general and convenient synthetic methodology for the synthesis of 1, 2 and its spiroketal-enol ether derivatives is described. Thus, 3-(2′-furyl)-propan-1-ol 7a or 4-(2′- furyl)-butan-1-ol 7b prepared from furaldehyde was treated with n-butyl lithium and ...