Nonane constitutional isomers

The Ordered Row Sums of HD Matrix for 35 Nonane Constitutional Isomers Listed Lexicographically... 

These dianhydrohexoses constitute a complete series of eight isomers having rigid tricyclic skeletons, such as 3,8,9-trioxatricyclo[4.2.1.02 4]nonane and 3,7,9-trioxatricyclo[4.2.1.02 4]nonane, respectively, as represented here by l,6 2,3-dianhydro-4-deoxy- (131) and 1,6 3,4-dianhydro-2-dcoxy-/J-o-n o-hexopyranose (132). 

Direct irradiation of an argon degassed 0.001 M pentane solution of cyclonona-1,2-diene (1) with wavelengths > 220 nm (Vycor filter) yielded bicyclo[6.1.0]non-l(9)-ene (6), cyclononyne 7 and tricyclo[4.3.0.0 ]nonane (3), ratio 94 3 3, as primary photoproducts. At low conversion of 1 (<20%) these isomers constituted more than 95% of the photoproducts higher conversions led to significant secondary reactions of bicyclo[6.1.0]non-l(9)-ene (6). 

---