Stereoselective synthesis of cyclic ethers via bromine assistedepoxide ring expansion
โ Scribed by Stephen G. Davies; Mario E.C. Polywka; Susan E. Thomas
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- French
- Weight
- 115 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0040-4039
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๐ SIMILAR VOLUMES
Fluorinated five-to seven-membered cyclic ethers were stereoselectively synthesized from four-to six-membered cyclic ethers having an iodoalkyl substituent by fluorinative ring-expansion reaction using p-iodotoluene difluoride.
The transannular cyclization of (Z,Z)-1-hydroxy-cyclonona-2,6-diene by iodonium assisted oxirane ring expansion was studied. The regioselectivity for the 14.3.11 vs t5.2.11 lo-oxabicyclo decane skeletons is high, and the iodine addition is also highly trans-selective. The results are rationalized in
## Abstract Bicyclic ketals in the 6,8โdioxabicyclo[3.2.1]octane system readily reacted with triethylsilaneโboron triโfluoride etherate at room temperature to give only the __cis__โtetrahydropyranol derivatives __via__ C~5~โO~6~ bond cleavage. __Threeโ__ and __erythro__โalcohols were prepared selec