An improved catalytic OsO4 oxidation of olefins to -1,2-glycols using tertiary amine oxides as the oxidant

The anionic ring-opening polymerization of five-membered cyclic carbonates fused to the cyclohexane ring

“…The trans-and cis-cyclohexane-1,2-diols were prepared from cyclohexene according to the literature. 26,27 All other chemicals were commercially available and used as received.…”

“…26 Cis-cyclohexane-1,2-diol was synthesized by the oxidation of cyclohexene with osmium tetroxide in the presence of N-methylmorpholine N-oxide. 27 Trans-and cis-1 were synthesized from ethyl chloroformate and the corresponding diols. The structures of the monomers were confirmed by 1 H and 13 C NMR.…”

Stereoselective synthesis of 1-deoxynojirimycin, D-glucono-δ-lactam and D-altrono-δ-lactam from a common chiral intermediate derived from D-mannitol

“…Then we applied the modified SAD conditions on ester 10 (entry 4) and the reaction was completed in 3 days and compound 15b was obtained in good yield with improved diastereoselectivity (dr = 15a:15b, 3:97). However, better results were obtained under Upjohn conditions, on treatment of the compound 10 with 5 mol % of OsO4 and N-methylmorpholine oxide (NMO) 16 as re-oxidant at 0 o C (entry 5). The reaction was After completion of these dihydroxylation experiments on the ester 10, we turned our attention to the synthesis of 1-deoxynojirimcycin (Scheme 4).…”

“…[]D 25 = -15.2 (c 0.5, CHCl3, compound synthesized using OsO4); IR (neat): (νmax, cm -1 ) 3414, 2937, 2861, 2103, 1448, 1277, 10991 H NMR (CDCl3, 300 MHz): δH 7.34-7.29 (m, 10H, Ar-H), 4.76 (d, J 10.9 Hz, 1H, benzylic CHaHb), 4.63 (d, J 10.9 Hz, 1H, benzylic CHaHb), 4.56 (s, 2H, benzylic CH2), 4.45 (br d, J 4.1 Hz, 1H, CHOH), 4.30-4.20 (m, 2H, CH2CH3), 4.09-4.02 (m, 2H, CHOH, CHOBn), 3.82-3.70 (m, 3H, CH2OBn, CHN3), 3.12 (br d, J 5.2 Hz, 1H, OH), 2.65 (br d, J 8.6 Hz, 1H, OH), 1.30 (t, J 7.1 Hz, 3H, CH3); 13 C NMR (CDCl3,75 MHz): δC 173.5,137.4,137.4,128.4,128.0,127.9,127.8,127.7,78.8,74.1 73.4,71.5,70.3,69.2,62.6,62.2,14 (16). A solution of ester 15a (2.15 g, 5 mmol) and PTSA (11 mg, 0.5 wt%) in 2,2-dimethoxypropane (DMP) (4 mL) and dry acetone (8 mL) was stirred at room temperature for overnight.…”

A Short and Efficient Synthesis of (2S,3S,4S)-tert-Butyl 3,4-Dihydroxy-2-(methoxymethyl)-5-oxopyrrolidine-1-carboxylate

“…In this paper we present our recent findings in the synthesis of the C33-C37 fragment of calyculin C. The synthesis commenced from Z-enoate 2, which can easily be synthesized starting from commercially available L-serine in five steps. 7 Dihydroxylation under the Upjohn conditions (OsO 4 , NMO) 9 provided the diol 3a in a modest 50% isolated yield. It is well known that electron-deficient double bonds are slug- gish towards osmylation.…”