Naked sugars as synthetic intermediates. Total synthesis of L-daunosamine

Monosaccharides and Analogues from Simple Achiral Unsaturated Compounds

“…Compound 8 could be transformed into deoxypolyoxin C. [5] It also permitted the first synthesis of (+)-d-allonojirimycin (Scheme 2). [6] l-Daunosamine [7] was also obtained from chiron 1. [8] The 'naked sugars' have been converted into long-chain sugars and C-disaccharides, [9] castanospermine and derivatives, [10] and to the Other enantiomerically pure 7-azabicyclo[2.2.1]heptane analogues, such as compounds (-)-15, (+)-16 [18] and (+)-17 [19] and their corresponding enantiomers, were also reported by Vogel's group (Scheme 5).…”

Rapid formation of complexity in the total synthesis of natural products enabled by oxabicyclo[2.2.1]heptene building blocks

“…This is opposite to the nitrile intermediate 52, which is expected to be preferentially attacked by X À at C5 due to the electron-withdrawing abilities of substituents at C2. Examples found in the literature include chloroselenation, 45 bromoselenation, 46 bromination 47 as well as chlorosulfenylation. 48 The centre alpha to the carbonyl group in 2 can be substituted with high stereoselectivity and the products transformed into a variety of compounds including sugar derivatives.…”

The optical resolution of bicyclo[2.2.1]hept-5-ene-2-cyanohydrins using brucine – a crystallographic and molecular-mechanics study

“…For one of the complexes, the primary interaction was shown to be formation of a hydrogen bond between the OH group of the alcohol and N19 of brucine (Toda, Tanaka & Ueda, 1981;Toda, Tanaka, Ueda & Oshima, 1985). Applying this technique to the cyanohydrin mixture, (2)/(3), formed by (+)-bicyclo[2.2.1]hept-5-en-2-one (4) and (+)-7-oxabicyclo[2.2.1]hept-5-en-2-one (5), we have been able to prepare optically pure (+)-(4) and (+)- (5), and also to use the resolved brucine/cyanohydrin complexes directly as synthons for the preparation of natural compounds (Black & Vogel, 1984;Warm & Vogel, 1986a,b, 1987Vogel, Fattori, Gasparini & LeDrian, 1990;LeDrian & Greene, 1982). We have thus determined the structures of the brucine complexes (6) and (7) of the cyanohydrins derived from (+)- (4) (7) X = 0 resolution by this technique.…”