Improved methods in the synthesis of 1α-hydroxylated vitamin D

Toh, Seok Si; Ngiam, Tong Lan; Wan, Lucy S.C.; Leung, S.L.

doi:10.1016/0039-128x(91)90111-8

Cited by 3 publications

(3 citation statements)

References 11 publications

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“…We next tested the transformation of trienone with a mixture of acetyl chloride, acetic anhydride and pyridine, which was another system of enol acetylation reported by Toh's group. 10 We found that the reaction proceeded well employing this system and the product 5 was obtained in higher yield (85%), after crystallization from methanol. Next, the cholesta-1,5,7-trien-3β-ol (6) was carried out by reduction of tetraene 5 with Ca(BH 4 ) 2 in ether at 0 °C (Scheme 1).…”

Section: Resultsmentioning

confidence: 68%

“…White crystals, mp 175.2-178.7 °C (lit. (10). To a stirred solution of the bromohydrins 9 (1.39 g, 2.0 mmol) in methanol (25 mL), K 2 CO 3 (1.38 g, 10 mmol) was added.…”

Section: Methodsmentioning

confidence: 99%

“…The residue was subjected to column chromatography on silica gel (hexane:AcOEt, 4:1) to yield compound 10 (1.03 g, 93%). Epoxide (10). White crystals, mp 169.5-171.2 °C (lit.…”

Section: Methodsmentioning

confidence: 99%

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A new synthetic method of 1β- and 2β-hydroxyprovitamin D3, the precursor of the 1β- and 2β-hydroxyvitamin D3

Sun¹,

Jin²,

Su³

2016

Arkivoc

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A new method was described for the synthesis of 1β-and 2β-hydroxyprovitamins D 3 , the photoprecusors of 1β-and 2β-hydroxyvitamin D 3. The key step of stereoselective introduction of C-1 and C-2 hydroxy groups was performed with a very mild method for the hydroxybromination of the D-A cyclo adduct with tribromoisocyanuric acid(TBCA)/water. The newly developed method requires no toxic or expensive reagents and 1β(2β)-hydroxyprovitamin D 3 was obtained with excellent yield and stereoselectivity.

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Section: Resultsmentioning

confidence: 68%

“…White crystals, mp 175.2-178.7 °C (lit. (10). To a stirred solution of the bromohydrins 9 (1.39 g, 2.0 mmol) in methanol (25 mL), K 2 CO 3 (1.38 g, 10 mmol) was added.…”

Section: Methodsmentioning

confidence: 99%