Which of the following is a bridged bicyclic alkane?

Question

a.bicyclo[3.2.0] heptane
b.bicyclo[2.2.1] heptane
c.cis-decalin
d.bicyclo[4.1.0] heptane
e.none of the above

Answer 1

it's b. if the last digit is not a 0, then you know it is bridged because there is at least one cabon between the bridge-heads.

Answer 2

THE ANSWER IS "b"

A bicyclic molecule contains two fused aliphatic rings. Fusion can occur at a single atom (spirocyclic), at two mutually bonded atoms or across a sequence of atoms (bridgehead). All these systems occur frequently in naturally-occurring organic compounds. An example is norbornane (bicyclo[2.2.1]heptane).

Bicyclic molecules have a strict nomenclature.[1] On its simplest level the parent hydrocarbon is the equivalent open carbon alkane. In front of it is added the prefix bicyclo and between brackets and in descending order the number of carbon atoms in each of the rings not counting the bridgeheads. For example in bicyclo[2,2,1]heptane the carbon frame contains a total of 7 atoms hence the parent name heptane. This molecule has three bridges having 2, 2 and 1 carbon atoms hence the prefix bicyclo[2,2.1].

Answer 3

b. Bicyclo[2.2.1]heptane. The structure is cyclohexane (a hexagon) with a -CH2- group in the center, bridging atoms 1 and 4. The presence of a 0 in two other names indicates that there is no bridging atom. (a.) looks like a pentagon sharing a side with a square. (d.) looks like a hexagon sharing a side with a triangle. (c.) could also be called bicyclo[4.4.0]decane, and looks like two hexagons sharing a side.