Unexpected effect of protecting group and solvent on the stereoselectivity of m-CPBA epoxidation of diprotected cis-4,5-dihydroxycyclohexenes

✍ Scribed by Simon E. de Sousa; Alex Kee; Peter O'Brien; Simon T. Watson

• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 257 KB
• Volume: 40
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(98)02319-3

✦ Synopsis

The stereoselectivity of m-CPBA epoxidation of diprotected cis-4,5-dihydroxycyclohexenes has been studied as a function of protecting group, solvent and in one example, epoxidising reagent. Three different ways of obtaining high levels of trans diastereoselectivity have been uncovered. In addition, the results suggest that bulky silyl protecting groups (eg triethylsilyl and tert-butyldimethylsilyl) can, in CH2C12, behave as moderate c/sdirectors v/a hydrogen bonding to m-CPBA.