SYNTHESIS AND APPLICATIONS OF TETRAHYDROFURAN-STABLE SUBSTITUTED (3-LITHIOXYALKYL)LITHIUMS AND (4-LITHIOXYALKYL)LITHIUMS, MODIFIED WITH MAGNESIUM 2-ETHOXYETHOXIDE

Substituted hydroxyalkyl phenyl sulfides 3 have been synthesized from the corresponding allylic or homoallylic alcohols 2. Regiospecific cle avage of the C-SPh bond of the sulfides 3 by lithium dispersion in tet rahydrofuran (THF) led to the synthesis of substituted (3-lithioxyalky l)- and (4-lithioxyalkyl)lithiums 4, most of which share the omega car bon with a carbocyclic ring. The organolithiums were modified with mag nesium 2-ethoxyethoxide in order to suppress their reactivity toward T HF cleavage, thus offering the advantage of preparing storable etherea l solutions of certain types of (lithioxyalkyl)lithiums. This strategy appears to be of rather broad scope. The functionalized organolithium s prepared in this way react normally with electrophilic reagents with yields in the range 35-55%. Thus, carboxylations of 4 yielded lactone s 5, some of which are natural products, while reactions of 4 with ben zophenone and cyclic ketones yielded 1,4- and 1,5-diols 6 and 7, respe ctively.