Reaction of 3-zircona-1-cyclopentenes and zirconacyclopentanes with aldehydes. A selective and convenient synthesis of 4-penten-1-ols, (Z)-5-iodo-4-penten-1-ols, and related alkanols

✍ Scribed by Christophe Copéret; Ei-ichi Negishi; Zhenfeng Xi; Tamotsu Takahashi

• Publisher: Elsevier Science
• Year: 1994
• Tongue: French
• Weight: 273 KB
• Volume: 35
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)75793-5

✦ Synopsis

3-Zircons-l-cyclopentenes and zirconacyclopentanes react with aidehydes at or below 25 OC to give the correspondmg carbonyl addition pmducts. i.e., 'I-membered oxazirconacycles, which can be readily converted to the corresponding alcohols via protonolysis and S-iodoalcohols via iodinolysis; the latter product can be further converted to 7-membeti lactones via Pd-catalyzed carbonylation.

We recently reported that 3-zircona-1-cyclopentenes (1) react with akynes, nitriles. and aldehydes to undergo coupling of these added nzagents with the alkenylidene moiety of 1 with concomitant extrusion of ethylene.' In each of the reactions of aldehydes. however, a minor amount of another pmduct was obtained at 50 OC. To our surprise. this became the major product, when the Ieaction was nm at lower temperatures (QS "C). In the reaction of la with FWHO.