A new method for the synthesis of diamantane by hydroisomerization of binor-S on treatment with sulfuric acid

• Rishat I. Aminov and
• Ravil I. Khusnutdinov

Beilstein J. Org. Chem. 2020, 16, 2534–2539, doi:10.3762/bjoc.16.205

• reaction stops after the hydrogenation step giving endo-endo-pentacyclo[7.3.1.12,5.18,10.03,7]tetradecane in 68% yield with excellent selectivity (100%). Keywords: binor-S; diamantane; hydroisomerization; sulfuric acid; tetrahydrobinor-S; Introduction Among the highly diverse polycyclic and cage

• binor-S (2) in cyclohexane in the presence of 98% sulfuric acid ([2]/[H2SO4] = 1:10–50) during 7–15 h affords a mixture of endo-endo-pentacyclo[7.3.1.12,5.18,10]tetradecane (tetrahydrobinor-S, 3c) and diamantane (1) (Table 1). An increase in the sulfuric acid ratio to binor-S (2) ([2]/[H2SO4] = 1:20–50

• deuterium atoms, occurs at the hydroisomerization step (experiment C). As shown by further studies, when the sulfuric acid concentration decreases to 75–80%, the reaction stops at the intermediate step giving endo-endo-pentacyclo[7.3.1.12,5.18,10.03,7]tetradecane (tetrahydrobinor-S, 3с; Scheme 3). It should