No abstract

Menthyloxymethoxy] -(E)-but-2-enyl(tributyl)stannanes (8) and (9), whose configurations were assigned by correlation with ( 2 R )and (2S)-pentan-2-01 (14) and (15), react stereoselectively on heating with benzaldehyde to give (3S,4S)and (3R,4R) -4hydroxy-3methyl-(Z) -1,2-enol ethers (I 6) and (1 8), respectively, the configurations of these products being -i-Prt.

No abstract

Lewis Acid-catalysed Reactions of 2.2.2-Trichloroethyl6-Diazopenicillanate and Imi nes: Rearrangements of Spi ro-6-Azi ridine-and Spi ro-6-oxi ranepen ic i I I a nates. X -Ray C ryst a I St ruct u res of (3S,6'S] -2,2,2-Trichloroeth y/ 3-[ 4-N it rophenyl) -1 -phenylspi ro [aziridi ne-2.6'-penici I lanate] and (3S.7aR) -2,2,2-Tric h loroet hyl2,3,5,7a -Tet ra hyd ro-7-met hoxy-2.2-d imet hyl -6-(4nit rophenyl ) -5oxopyrrolo[2.1 -b]thiazole-3-carboxylate

The spiro-aziridine-azetidinones (8), ( 9), ( 12)-(17) were prepared by heating equimolar amounts of 6-diazopenicillanate (1) and aromatic imines under reflux in chloroform; the structures of the analogues (18) and (19), prepared from cinnamylidene p-methoxyaniline, were established by X-ray diffraction, as was the structure of the monocyclic P-lactams (10) and (11) formed by heating the benzylidene aniline adducts (8) and (9) under reflux in toluene.The chemistry of 6-diazopenicillanates has been studied with a view to preparing penicillin analogues with a wide variety of different substituents at C(6);l for example Lewis acid catalysed reactions between 6-diazopenicillanate (1) and aromatic aldehydes and imines have led to the formation of spiro-epoxides (2) and spiro-aziridines (3) together with rearranged products formed by C(5)-C( 6) bond cleavage. *We now report some preliminary observations on the thermal reactions between 6-diazopenicillanate (1) and aromatic imines which have revealed an unusual and intriguing p-7 Deceased 8th December, 1984.