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The palladium(II)-catalyzed cyclization of the urethane 8, which was derived from D-mannitol, gave the cyclic compound 9 with excellent diastereoselectivity. During these transformations, the Pd(II) species are not reduced and thus the catalyst can recycle without its reoxidation. The cycloadduct 9 was converted to 1-deoxymannojirimycin.

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The stereochemistry was studied concerning the ring expansion of some 2-isopropenylcyclopropane-1-carbonyl compounds to 2,5-dihydro-3-methyloxepin derivatives. The LAH reduction of dimethyl 2-isopropenylcyclopropane-1,1-dicarboxylate (1aa) gave the corresponding diol, and a subsequent Swern oxidation gave a seven-membered 4,7-dihydro-6-methyloxepin-3-carbaldehyde. A DIBAL reduction of 1aa gave two isomeric hydroxymethyl carboxylic esters, and a subsequent Swern oxidation of methyl 1-hydroxymethyl-t-2-isopropenylcyclopropane-r-1-carboxylate caused a ring expansion to give methyl 4,7-dihydro-6-methyloxepin-3-carboxylate; however, a similar Swern oxidation of methyl 1-hydroxymethyl-c-2-isopropenyl-cyclopropane-r-1-carboxylate caused no ring expansion to give methyl 1-formyl-c-2-isopropenylcyclopropane-r-1-carboxylate.

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Palladium(II)-catalyzed cyclization of optically active urethanes containing an allylic alcohol moiety was examined. Efficient 1,4-asymmetric induction was found in this reaction. The cycloadducts were converted to pseudoconhydrine.