S-AUyly-hydroxy ketenedithioacetals[ la-le ] underwenta mpid and diastereoselectivethio-Claisen mrrarrgementinto anti cs-allyl &hydroxydithioesters[ 2a.2e ] over various zeolites at room temperaturein hexaneis descriked.O 1997Elsevier ScienceLtd.
Thio-Claisenrearrangementshave been extensivelystudiedin the past under variousconditionsbut not receivedas muchattentionas normalClaisenrearrangements. ' Recentlya new Claisenprotocol,dealingwith the highly diaste~oselectivethio-Claisenturmngement of S-allyl ketene dithioacetalsand S-methallylN-nitro thioacetylpyrrolidinewere reported.2'3Achievingstereoeontrolin the constructionof acyclic systems is a challenginggoalin organicsynthesis.4 Eventhoughtherehavebeenseveralreportson asymmetricinductionin [3,3] sigmatropicrearrangementsno reportis availablein the literatmein whicha zeoliteis employedeither to promotethethio-Claisenrearrangement orfor the chid induction. Theuniquecharacteristics of zeolitessuch as shapeselectivity,thermalstability,acidicandbasicpropertiescoupledwith the ease of operationhavemade the interfaceof organicsynthesisandzeolitecatrdysisanimportant researcharea.c In this communication we wish to report the synthetic utility of zeolites (Y, EMT, ZSM-5 and Zeolite beta) as a versatile catalyst for