Convenient synthesis of d- and l-xylo-1,2,3,4-alkane tetrols from a d-gluco-configured common building block

Tandem IBX‐Promoted Primary Alcohol Oxidation/Opening of Intermediate β,γ‐Diolcarbonate Aldehydes to (E)‐γ‐Hydroxy‐α,β‐enals

“…(2S,3S,4R)‐Icosane‐1,2,3,4‐tetrayl tetraacetate, d ‐xylo‐C20‐guggultetrol ( 20 a ) and (2R,3R,4R)‐icosane‐1,2,3,4‐tetrayl tetraacetate, d ‐arabino‐C20‐guggultetrol ( 20 b ) . To a mixture of K 3 [Fe(CN) 6 ] (183.7 mg, 0.558 mmol, 3.0 equiv), K 2 CO 3 (77.1 mg, 0.558 mmol, 3.0 equiv), (DHQ) 2 PHAL (2.2 mg, 0.0028 mmol, 1.5 mol %) in t BuOH‐H 2 O (1:1, 1 mL) cooled at 0 °C was added K 2 OsO 4 .2H 2 O (0.8 mg, 0.00188 mmol, 1.0 mol %) followed by methanesulfonamide (18.6 mg, 0.186 mmol, 1.0 equiv).…”

A Concise Stereoselective Synthesis of Naturally Occurring d‐Xylo‐C18‐Guggultetrol and its C2‐Epimer

“…The residue was purified by silica gel column chromatography using petroleum ether/EtOAc (9 : 1) as eluent to give 8 a (25 mg, 83%) as a viscous oil. [α] D 25 =+1.5 ( c =1.0, CHCl 3 ), lit . [α] D 25 =+1.3 ( c =1.0, CHCl 3 ); IR (CHCl 3 ): ν max =2917, 2850, 1739, 1466, 1451, 1374, 1222, 1038, 1027, 975, 914, 856, 738, 629 cm −1 ; 1 H NMR (CDCl 3 , 400 MHz) δ = 5.30–5.20 (m, 2H), 5.12–5.06 (m, 1H), 4.36 (dd, J =12.0, 3.7 Hz, 1H), 3.96 (dd, J =12.0, 5.5 Hz, 1H), 2.09 (s, 3H), 2.08 (s, 3H), 2.07 (s, 3H), 2.05 (s, 3H), 1.56–1.30 (m, 2H), 1.27–1.20 (m, 24H), 0.87 (t, J =6.7 Hz, 3H); 13 C NMR (CDCl 3 , 100 MHz) δ=170.4, 170.36, 170.0, 169.99, 71.4, 71.3, 69.6, 62.0, 31.9, 30.6, 29.7, 29.64, 29.6, 29.5, 29.4, 29.3, 29.25, 24.9, 22.7, 20.9, 20.8, 20.7, 20.6, 14.1; HRMS (ESI‐TOF) m/z : [M+Na] + calcd for C 26 H 46 O 8 Na 509.3085, found 509.3084.…”

“…Sudalai and co‐workers described enantioselective synthesis of 1 a employing Sharpless asymmetric epoxidation and dihydroxylation reactions. The synthesis of both D‐ and L‐ xylo guggultetrols ( 1 a and ent ‐ 1 a ) by Aidhen and co‐workers employed D‐gluconic acid δ‐lactone and involved overall 10 and 14 steps respectively. Subsequently, two of the C18‐guggulterol stereoisomers were prepared by Sridhar et al .…”

Synthesis of Bulk Kesterite – A Prospective Photovoltaic Material

“…Remarkably, treatment of the aldol adduct 8 with the mild reducing agent sodium borohydride (5.0 equiv) in ethanol at 40 °C provided the 2‐amino‐1,3‐diol 32 in 80 % yield (Scheme ), and the auxiliary was recovered quantitatively in pure form. We are aware of only one previous report of the reduction of tertiary amides (α‐hydroxy morpholinamides) to the corresponding alcohols with sodium borohydride 18. Reduction of pseudoephedrine and pseudoephenamine amides to the corresponding primary alcohols has historically been achieved using lithium amidotrihydroborate (LAB),2b, 3b, 10 a much more reactive hydride donor that we introduced in 1996 19.…”