Lithiocyclopropylphenyl sulfide

CYCLOBUTYL ANNELATION 1-Lithiocyclopropylphenyl sulfide. CYCLODEHYDRATION Magnesium methyl carbonate. Pyridine hydrochloride. CYCLODEHYDROGENATION Sodium aluminum chloride. 

In a novel approach, Trost and Keeley (102) used the annelation reagent lithiocyclopropylphenyl sulfide (85) to prepare first cyclobutanone (88) and then the fused biscyclobutane spiro system (89) as a mixture of diastereomers with the desired conformer in fom fold excess (Scheme 16). Haloform-type cleavage afforded cyclobutane derivative (90), which upon transformation of the various functionalities yielded grandisol. 

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