Bicyclic Alkanes Fused rings(稠环)share two adjacent carbons. Bridged rings(桥环)share two nonadjacent C's. bicyclo[3.1.0]hexane bicyclo[2.2.1]heptane Bicyclic Alkanes ▪Fused rings（稠环）share two adjacent carbons. ▪Bridged rings（桥环）share two nonadjacent C’s. bicyclo[3.1.0]hexane bicyclo[3.1.0]hexane bicyclo[2.2.1]heptane bicyclo[2.2.1]heptane