Synthesis of tetraacetal tetraoxa-cage compounds with alkyl substituents at different sites of the oxa-cage skeleton

Abstract

Tetraacetal tetraoxa-cage compounds 3a, 3b, 4a, 4b, 7, 13, 14, and 15 were synthesized by a short sequence. They were obtained from ozonolysis of endo adducts 1a, 1b, 2a, 2b, and 6 in dichloromethane at -78 degrees C followed by reduction with dimethyl sulfide. Ozonolysis of 7-anti-trimethylsilyl-5,6-bis-endo-diacetylnorbornene 8 under the same reaction conditions did not give the tetraoxa-cage 9. The methylsulfinyl era-cage 13 derived from 1-methylthio-5,6-bis-endo-diacetylnorbornene 11 was converted to com pounds 14 and 15.