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

3-Zircona-1-cyclopentenes and zirconacyclopentanes react with aldehydes at or below 25 degrees C to give the corresponding carbonyl addition products, i.e., 7-membered oxazirconacycles, which can be readily converted to the corresponding alcohols via protonolysis and 5-iodoalcohols via iodinolysis; the latter product can be further converted to 7-membered lactones via Pd-catalyzed carbonylation.