(2R,3R,4S,6R)-2-benzyloxymethyl-3-bromo-6-(tert-butyldimethylsilyloxymethyl)tetrahydropyran-4-ol | 172328-31-3

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (2R,3R,4S,6R)-2-benzyloxymethyl-3-bromo-6-(tert-butyldimethylsilyloxymethyl)tetrahydropyran-4-ol
• 英文别名: (2R,3R,4S,6R)-3-bromo-6-[[tert-butyl(dimethyl)silyl]oxymethyl]-2-(phenylmethoxymethyl)oxan-4-ol
• CAS: 172328-31-3
• 化学式: C₂₀H₃₃BrO₄Si
• 分子量: 445.469
• InChiKey: RYLUGEVITMZUIK-FCGDIQPGSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.51
• 重原子数：
  26
• 可旋转键数：
  8
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.7
• 拓扑面积：
  47.9
• 氢给体数：
  1
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  (2R,3R,4S,6R)-2-benzyloxymethyl-3-bromo-6-(tert-butyldimethylsilyloxymethyl)tetrahydropyran-4-ol 在 草酰氯 、 偶氮二异丁腈 、 三正丁基氢锡 、 二甲基亚砜 作用下， 以 二氯甲烷 为溶剂， 反应 2.33h， 生成 (2S,6R)-2-benzyloxymethyl-6-(tert-butyldimethylsilyloxymethyl)tetrahydropyran-4-one
  参考文献：
  名称：

  Stereoselective synthesis of cis- and trans-2,6-disubstituted 5,6-dihydro-2H-pyrans based on 1,5-asymmetric induction in reactions between allylstannanes and aldehydes promoted by tin(IV) chloride

  摘要：

  The allyltin trichloride formed by treating [(4S)-5-(tert-butyldimethylsilyloxy)-4-(2-trimethylsilylethoxy methoxy)]pent-2-enyl(tributyl)stannane 9 with tin(IV) chloride, reacts stereoselectively with 2-oxoethyl toluene-p-sulfonate to give the syn-6-(2-trimethylsilylethoxymethoxy)hept-4-en-2-ol 10 which was converted into the epoxide 11 by treatment with potassium carbonate in methanol. After replacing the tert-butyldimethylsilyl ether by a benzyl ether, removal of the 2-trimethylsilylethoxymethoxy group using trifluoroacetic acid, gave the 2,6-cis- and 2,6-trans-disubstituted 5,6-dihydro-2H-pyrans 14 and 15, ratio 80:20, which were separated as their tert-butyldimethylsilyl ethers 16 and 17 and characterised as their acetates 18 and 19. The 5,6-dihydro-2H-pyrans 24 and 26, ratio 80:20, were similarly prepared from (4S)-4-(2- trimethylsilylethoxymethoxy)pent-2-enyl(tributyl)stannane 21. A complementary route to the trans-2,6-disubstituted 5,6-dihydro-2H-pyran 15 was developed from 2-oxoethyl benzoate which gave the syn-hydroxy ether 28 under the usual conditions. Mesylation and ester saponification gave the anti-epoxide 30 and, after replacing the tert-butyldimethylsilyl ether by a benzyl ether, treatment with trifluoroacetic acid gave the 5,6-dihydro-2H-pyrans 14 and 15, in favour of the trans-isomer, ratio 14:15 = 20:80. Improved stereoselectivity in these dihydropyran syntheses was obtained if the stannane 9 was treated with butyl glyoxylate in the first step. The cis-2,6-disubstituted 5,6-dihydro-2H-pyran 16 was converted into the tetrahydropyran-3-one 37 by hydroboration-oxidation, and into the tetrahydropyran-4-one 43 by treatment with bromine water, reductive debromination and oxidation.

  DOI：

  10.1039/p19950002487
• 作为产物：
  描述：

  (2S)-2-benzyloxymethyl-6-hydroxymethyl-5,6-dihydro-2H-pyran 在 N-溴代丁二酰亚胺(NBS) 、 三乙胺 作用下， 以 乙二醇二甲醚 、 二氯甲烷 为溶剂， 反应 19.0h， 生成 (2R,3R,4S,6R)-2-benzyloxymethyl-3-bromo-6-(tert-butyldimethylsilyloxymethyl)tetrahydropyran-4-ol
  参考文献：
  名称：

  Stereoselective synthesis of cis- and trans-2,6-disubstituted 5,6-dihydro-2H-pyrans based on 1,5-asymmetric induction in reactions between allylstannanes and aldehydes promoted by tin(IV) chloride

  摘要：

  The allyltin trichloride formed by treating [(4S)-5-(tert-butyldimethylsilyloxy)-4-(2-trimethylsilylethoxy methoxy)]pent-2-enyl(tributyl)stannane 9 with tin(IV) chloride, reacts stereoselectively with 2-oxoethyl toluene-p-sulfonate to give the syn-6-(2-trimethylsilylethoxymethoxy)hept-4-en-2-ol 10 which was converted into the epoxide 11 by treatment with potassium carbonate in methanol. After replacing the tert-butyldimethylsilyl ether by a benzyl ether, removal of the 2-trimethylsilylethoxymethoxy group using trifluoroacetic acid, gave the 2,6-cis- and 2,6-trans-disubstituted 5,6-dihydro-2H-pyrans 14 and 15, ratio 80:20, which were separated as their tert-butyldimethylsilyl ethers 16 and 17 and characterised as their acetates 18 and 19. The 5,6-dihydro-2H-pyrans 24 and 26, ratio 80:20, were similarly prepared from (4S)-4-(2- trimethylsilylethoxymethoxy)pent-2-enyl(tributyl)stannane 21. A complementary route to the trans-2,6-disubstituted 5,6-dihydro-2H-pyran 15 was developed from 2-oxoethyl benzoate which gave the syn-hydroxy ether 28 under the usual conditions. Mesylation and ester saponification gave the anti-epoxide 30 and, after replacing the tert-butyldimethylsilyl ether by a benzyl ether, treatment with trifluoroacetic acid gave the 5,6-dihydro-2H-pyrans 14 and 15, in favour of the trans-isomer, ratio 14:15 = 20:80. Improved stereoselectivity in these dihydropyran syntheses was obtained if the stannane 9 was treated with butyl glyoxylate in the first step. The cis-2,6-disubstituted 5,6-dihydro-2H-pyran 16 was converted into the tetrahydropyran-3-one 37 by hydroboration-oxidation, and into the tetrahydropyran-4-one 43 by treatment with bromine water, reductive debromination and oxidation.

  DOI：

  10.1039/p19950002487