On treatment with t-BuLi in the presence of HMPA, 2-, 3-or 4-methoxybenzamides (o-, m-or p-anisamides) bearing Nbenzyl substituents cyclise with dearomatisation to give methyl dienyl ethers which hydrolyse to give single stereo-and regioisomers of pyrrolidine-fused cyclohexenones. The bicyclic enones are versatile synthetic intermediates which undergo transformations such as stereoselective reduction and conjugate addition, regioselective Baeyer-Villiger oxidation, bromination and hydrogenation.The lithiation a to nitrogen of aromatic amides bearing benzylic substituents has been known for many years, with Fraser 1 and Durst 2 reporting the a-lithiation by LDA of N-benzylamides 1a, 2 and 3. In 1999, we reported 3 that the organolithiums derived from simple N-benzyl benzamides 1a and 1b are unstable at -78 °C in the presence of HMPA: they undergo a cyclisation reaction with loss of aromaticity in the benzamide ring, leading to pyrrolidinefused cyclohexadienes 5 and 6 (Scheme 1). The intermediate in the cyclisation reactions is an extended enolate 4, which unfortunately does not react regioselectively with electrophiles -a serious limitation to the synthetic application of the dearomatising reaction.In this Letter, we now report that benzamides 7-9 and 11 bearing methoxy groups also cyclise with dearomatisation, but that the regioselectivity of the electrophilic quench step is immaterial to the formation of single final product because hydrolysis of a mixture of first-formed dienyl ethers usually generates a single regioisomer of a cyclohexenone. The cyclohexenone products are versatile synthetic intermediates which undergo stereoselective functionalisation. 4The four anisamides (methoxybenzamides) 7, 8, 9a and 9b were made by acylation of N-benzyl-t-butyl amine or N-p-methoxybenzyl-t-butyl amine. Amide 11 was made by ortholithiation 5 and benzylation of the secondary benzamide 10 (Scheme 2). They were each treated under our standard conditions 3 for dearomatising cyclisation (Method A: t-BuLi, THF, HMPA, -78 °C, or, for 8 and 11, -40°C) and the reactions were quenched with aqueous ammonium chloride (Scheme 3).The o-anisamide 7 was the only amide to cyclise with a lack of stereoselectivity, giving 76% of the cyclised product 12 as a mixture of stereoisomers, 6 which were separable by flash chromatography on silica, though slightly unstable. Each of exo-and endo-12 was obtained as a single regioisomer only. The m-anisamide 8, which in principle could cyclise onto either the 2-or the 6-position of the ring, similarly gave only a single regioisomer 14, but the cyclisation required temperatures of -40 °C to return good yields of 14. The p-anisamides 9a, 9b and 11 cyclised stereoselectively, but sometimes gave mixtures of regioisomers arising from a-or g-attack on the enolate intermediate. 16a and 16b were typically obtained as single regioisomers; 7 19a and 19g were obtained in a 5:1 ratio; and 18a and 18g (produced by alkylating the intermediate enolate with MeI) were obtained in a 1:2 ratio. N O Ph R N O Ph R 1a, R ...