Swern

FIG. 23-34 Effeot of reaction pressure and temperature on tLe rate of hydrogenation of soybean oil. (Swern, ed., Baileys Industrial Oil and Fat Products, ijol 2, Wiley, 1979. )... 

Figure 23-36 shows a computer calculation with these specific rates, but which does not agree quantitatively with the figure shown by Swern. The time scales appear to be different, but both predict a peak in the amount of oleic acid and rapid disappearance of the first two acids. 

N-Methyllauramide, N-methyhnyristamide, and N-methyl-pelargonamide can be prepared in 95-98% yield by adaptation of the method used by Roe, Scanlan, and Swern for the preparation of amides of oleic and 9,10-dihydroxystearic acids. 

Swern, D Organic Peroxides, Wiley New York, 1973, Vol 2, p403... 

The 6-endo activated epoxy alcohol cyclization process was also expected to play a central role in the annulation of pyran ring G of the natural product (see Scheme 22). Silylation of the free secondary hydroxyl group in compound 131 furnishes, after hydrobora-tion/oxidation of the double bond, compound 132. Swern oxidation of alcohol 132 produces an aldehyde which reacts efficiently with (ethoxycarbonylethylidene)triphenylphosphorane in the presence of a catalytic amount of benzoic acid in benzene at 50 °C, furnishing... 

Swern oxidation of N-unsubstituted aziridine-2-carboxylate 210 (Scheme 3.77) resulted in the formation of 2H-azirine 211 in >90% yield [95] Similar oxidation of 212 (Scheme 3.78) afforded azirine 213 in 60% yield [66]. 

Swern oxidation of N-unsubstituted aziridine-2-phosphonates resulted in the formation of both 2H-azirine-2-phosphonates and 2H-azirine-3-phosphonates [81, 83]. Treatment of ds-aziridine-2-phosphonate 226 (Scheme 3.84) with DM SO/ (COCl)2/Et3N afforded azirine-phosphonates 227 and 228, with the former predominating [81]. Under similar conditions, however, trans-aziridine-2-phospho-... 

In our work with aminolysis of vinylepoxides (see Section 9.2.1.1), the substrates were routinely synthesized by SAE followed by Swern/Wittig reactions (Table 9.3, Entries 1-4) [48, 49]. This procedure is well suited for terminal olefins, but dis-ubstituted olefins can seldom be obtained with useful (E Z) selectivities. Nakata recently synthesized some advanced intermediates towards natural products in this manner (Entries 5, 6) [50, 51]. 

Recently, several one-pot oxidation-Wittig procedures that circumvent the need to isolate the intermediate aldehydes have been developed. Various oxidants, including Swern [52], Dess-Martin periodinane [53], IBX [54], Mn02 [55], and BaMnCU [56], can be used in the presence of stabilized ylides to generate a,(3-unsaturated esters. 

Epoxidation of olefins with meta-chloroperbenzoic acid, (MCPBA) remains to this day among the most widely used methods for research-scale applications [16], Discovered by Nikolai Prilezahev in 1909 [17], it became popular only decades later, mostly through the works of Daniel Swern in the 1940s [18]. Despite its simplicity, and not unlike most epoxidation methods in use today, it suffers from undesired epoxide opening caused by the slight acidity of the reaction milieu. Although acid-catalyzed side reactions can sometimes be minimized by use of buffered systems... 

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