Diastereoselective ene reactions of triazolinediones with chiral allylic alcohols. Evidence for a hydroxyl-enophile steering effect

✍ Scribed by Manolis Stratakis; Georgios Vassilikogiannakis; Michael Orfanopoulos

• Publisher: Elsevier Science
• Year: 1998
• Tongue: French
• Weight: 303 KB
• Volume: 39
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(98)00207-x

✦ Synopsis

The ene reaction of PTAD with the chiral allylic alcohol 4-methyl-3-penten-2-01 exhibits high threo diastereoselectivity in non polar solvents, whereas in polar solvents the diastereoselectivity decreases substas!ially. These results are discussed in terms of a steering effect between the hydroxyl and the incoming enophile during the formation of the diastereomcric syn and anti aziridinium imide intcrrmdiatcs.