A new synthetic route to -silyl ketones involving two steps from readily available components is described. Recentlywe have described the generation of 2lithio derivatives (2) from 1,3-dithianes (1) and the application of these nucleophilic reagents to the synthesis of a wide variety of organic compounds, including aldehydes, ketones, l,n-diketones, a-hydroxy ketones, -keto acids, and -amino ketones.1 The

Until recently, broth cultivation techniques for Campylobacter pylori were unavailable. We developed a method to cultivate bacterial cells within 24 h in liquid media. Cultivation in broth depended on the adequate dispersion of appropriate gases. A static broth at 37°C in a GasPak jar (BBL Microbiology Systems, Cockeysville, Md.) with a CampyPak (BBL) envelope did not support growth after 5 days of incubation. A broth placed in a flask on a Gyrotory water bath shaker (150 rpm; New Brunswick Scientific Co., Inc., Edison, N.J.) fitted with a gassing hood connected to a gas mixture of 10% C02, 5% 02, and 85% N2 supported good growth. An initial inoculum of 105, 103 to 104, or 102 CFU/ml resulted in >108 CFU/ml after incubation for 24, 48, or 72 h, respectively. Under these conditions, the bacteria grew as motile, spiral bacilli rather than the oval and coccal bacilli occasionally reported. Several bases supported good growth when supplemented with serum. For the determination of basal growth conditions, brucella broth base was used. Fetal calf serum (1%) provided maximum growth. Vitox was not necessary for growth and did not augment growth. C. pylori grew over a wide optimal pH range of 5.5 to 8.5.

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Aseries of cephalosporins derived from cephalothin containing an ester-linked quinolonyl substituent at the C-10 position (C-10 quinolonyl-cephem esters) has been prepared and evaluated for in vitro antibacterial activity. The C-10 quinolonyl-cephem esters exhibited a broadened spectrum of activity when compared with cephalothin and the corresponding quinolones, including activity against /Mactamase-producing bacteria. cephalothin which culminated in the highly potent, broad spectrum agent le (Fig. 1). These compounds (la~le, Fig. 2, herein referred to as C-10 quinolonyl-cephem esters) possess a quinolonyl moiety attached at the C-10 position of cephalothin by an ester linkage through the quinolone-3-carboxylate. The synthetic procedures described in this report allow for the preparation of such C-10 quinolonyl-cephem esters with minimal formation of undesired z!2-cephem side products.Chemistry The preparation of la~le proceeded as shown in Fig. 3. The coupling of the 10-iodocephem 4-nitrobenzyl ester 211>12) with nalidixic acid sodium salt (3a) in A^N-dimethylformamide (DMF) gave a mixture of the desired z!3-cephem adduct (4a) and 30~40%of the thermodynamically more stable z!2-isomer. The quinolone carboxylate is sufficiently basic to abstract a proton from the cephalosporin Fig. 1. Structure ofle.