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5-(Hydroxymethyl)-2-pyrrolidmone (3), prepared from L-pyroglutamic acid, was condensed with benzaldehyde to obtain the 0,iV-acetal 4 in excellent yield. Alkylation of 4 with 3-bromocyclohexene followed by reduction gave ímras-4-cyclohexyl-L-prolmol (7) in good chemical yield with excellent stereoselectivity. Sequential N-protection, oxidation of the alcohol to the acid, and N-deprotection furnished trons-4-cyclohexyl-L-proline (1) in excellent yield and quality. Compound 1 serves as an intermediate for the preparation of ACE inhibitors including Fosenopril.

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3-eftdo-Hydroxy-5-endo-carboxybicyclo [2.2.2] octane Lactone (6).-The published methods6 were modified as follows. Bicyclo-[2.2.2]oct-2-ene-5-carboxylic acid5•6 (100 g) in 720 ml of 30% (v/v) H2S04 was stirred and heated at 110°for 1 hr. The mixture was cooled, poured onto ice, and extracted with CHClg. The extract was washed with 10% NaHCOs, dried over MgS04, filtered, and concentrated under reduced pressure, yielding 74.3 g of 6, mp 207-208°.3-endo-Hydroxy-5-endo-carbamylbicyclo [2.2.2] octane (7) .-A solution of 500 mg of 6 in 10 ml of MeOH and 10 ml of liquid NHs was heated at 110°for 12 hr. The reaction mixture .was concentrated under reduced pressure, and the residue was recrystallized from hot CHClg-petroleum ether, yielding 500 mg of 7, mp 188.

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