borohydride reduction 2 carbomethoxytropinone

Lactitol (4-0-p -D-galactopyranosyl-D-glucitol) is obtained by sodium borohydride reduction (99,100) or catalytic hydrogenation (101) of lactose. Xyhtol also is obtained by sodium borohydride reduction of D- xylonic acid y-lactone (32) and from glucose by a series of transformations through diacetone glucose (46). In turn, estrone methyl ether can be converted to estradiol methyl ether by sodium borohydride reduction of the C17 ketone (199,200).

9,11- Dehydroestrone methyl ether (177) can be converted to estrone methyl ether by stereoselective reduction of the C - double bond with triethyi silane in triduoroacetic acid. Ī McMurry coupling of (176, X = O Y = /5H) provides ( )-9,ll-dehydroesterone methyl ether (177) in 56% yield. ĭepending on experimental conditions, sodium borohydride reduction of anthraquinone, in a lower ahphatic alcohol, results in 9,10-dihydroxyanthracene. Nucleophilic addition to carbonyl groups sometimes leads to a mixture of stereoisomeric products The direction of attack is often controlled by stenc factors with the nude ophile approaching the carbonyl group at its less hindered face Sodium borohydride reduction of 7 7 dimethylbicycloĭoes sodium borohydride reduction of o ribose yield an opti. Sodium borohydride and lithium aluminum hydride react with carbonyl compounds in much the same way that Grignard reagents do except that they function as hydride donors rather than as carbanion sources Figure 15 2 outlines the general mechanism for the sodium borohydride reduction of an aldehyde or ketone (R2C=0) Two points are especially important about this process. The conditions required for the sodium borohydride reduction of 2-amino-5-acylthiazoles are stronger than those used for the reduction of 2-acylamino-5-acylthiazole (476).

Borohydride reduction 2 carbomethoxytropinone