Dihydroxy-2-oxa-6-thia-adamantane

Desulfuration of the diol 25 (2.1.3.) with raney-nickel led to exo,exo-2,6-dihydroxy- 

9-oxabicyclo[3.3.1]nonane (404) in approx. 75% yield. Jones-oxidation of the latter 

2-Oxa-7-thia-isotwistane [148), 10 -Hydroxy-2-oxa-7-thia-isotwistane 335) and 10 -Acetoxy-2-oxa-7-thia-twistane 249) 

Treatment of unsubstituted 2-oxa-7-thia-isotwistane 148 2.2.3.1.) with raney-nipkel, yielded 74% of 9-oxabicyclo[4.2.1]nonane 408) and reductive desulfuration of the alcohol 335 (4.3.2.) 85% of endo-2-hydroxy-9-oxabicyclo[4.2.1 ]nonane (409) Analogous reaction of the 10 -acetoxy-twistane 249 (3.2.3.) with raney-nickelj however, led to endo-2-acetoxy-9-oxabicyclo[3.3.1]nonane (47( )  

---