1-[(1S,2S,4S,5R)-4-hydroxy-5-(hydroxymethyl)bicyclo[3.1.0]hexan-2-yl]thymine is a carbobicyclic compound that is bicyclo[3.1.0]hexane which is substituted at the 2-pro-S, 4-pro-S and 5-pro-R positions by thymin-1-yl, hydroxy, and hydroxymethyl groups, respectively. It is a primary alcohol, a secondary alcohol, a carbobicyclic compound, a C-glycosyl pyrimidine and a pyrimidone. It is functionally related to a thymine.