Synthesis and reactions of 1′,2:4,6-di-o-isopropylidene-sucrose

(2S,3S,4R,4a'R,5R,5a'R,11a'R,12′S,12a'R)-5-(Acetoxymethyl)-2′,2′,10′,10′-tetramethyloctahydro-3H,8′H-spiro[furan-2,7′-[1,3]dioxino[4′,5′:5,6]pyrano[3,2-d][1,3,6]trioxocine]-3,4,12′-triyl triacetate

While the crystal structure analysis of the title compound, C26H38O15, a synthetic derivative of sucrose, was originally reported 40 years ago [Drew et al. (1979). Carbohydr. Res. 71, 35–42], the present work has allowed for the determination of its absolute configuration through the application of resonant scattering techniques.

Synthesis and antitumor activity of lapathoside D and its analogs

Phenylpropanoid sucrose esters are important class of plant-derived natural products and have greater potential to be leads for new drugs because of their structural diversity and broad-array of pharmacological and biological activities. Regio- and chemo-selective acylation of 2,1':4,6-O-di-isopropylidene sucrose 4 with cinnamoyl chloride 5 and p-acetoxycinnamoyl chloride 6 afforded mono-, di-, tri- and tetra- variant PSEs in moderate yields. The first total synthesis of di-substituted PSE, lapathoside D 1' has been achieved successfully in short and simple synthetic steps from sucrose 3 as an inexpensive starting material. Lapathoside D 1 and a set of selected synthesized PSEs were tested for in vitro cytotoxicity against human cervical epithelioid carcinoma (HeLa) cell lines. Most of the compounds exhibited significant antitumor activity with their IC(50) values ranging from 0.05 to 7.63 μM. The primary screening results indicated that PSEs might be valuable source for new potent anticancer drug candidates.

Sucrose octabenzoate: assignment of 13C and 1H resonances of the sucrose moiety and the 13C resonances of the carbonyl carbons. Use of 13C-n.m.r. spectroscopy for the study of selective deacylation

Assignment of the 1H and 13C signals arising from the carbohydrate portion of sucrose octabenzoate has been achieved using homonuclear shift correlation experiments (COSY) and one-bond 1H-13C heteronuclear shift correlation measurements, respectively. The 13C resonances of the carbonyl carbon atoms of the eight benzoyl groups are readily distinguished for solutions in benzene-d6-pyridine-d5 (1:1), and have been assigned by means of three-bond 1H-13C shift correlation studies coupled with measurement of the 13C-n.m.r. spectrum of a sucrose octabenzoate specifically labelled with 13C in some of the carbonyl groups. With this assignment, products of partial deacylation of the octabenzoate may readily be identified by treatment with excess of benzoyl-carbonyl-13C chloride followed by measurement of the 13C-n.m.r. spectrum of the labelled sucrose octabenzoate, so prepared, in the carbonyl region.

2,3'-anhydrosucrose

Alkaline hydrolysis of alpha-D-glucopyranosyl 3,4-anhydro-beta-D-ribo-hexulofuranoside (1) involves participation of HO-2 and leads to 2,3'-anhydrosucrose (2). The structure of 2 was assigned on the basis of the n.m.r. and mass spectra of its hexa-acetate 3 and confirmed by the formation from 2 of the 6,6'-di-(4) and 6,1',6'-tri-O-trityl (5) derivatives, the 4,6-O-isopropylidene derivative (6), and 2,3':3,4-dianhydro-galacto-sucrose, isolated as the tetra-acetate 7. The structure of 7 was confirmed by its conversion into the 4'-O-tosyl-6,1',6'-O-trityl derivative 14 and by unambiguous synthesis from 6.