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【结 构 式】

【分子编号】57951

【品名】(2R,3S,6S)-6-ethoxy-2-(hydroxymethyl)tetrahydro-2H-pyran-3-ol

【CA登记号】

【 分 子 式 】C8H16O4

【 分 子 量 】176.21264

【元素组成】C 54.53% H 9.15% O 36.32%

与该中间体有关的原料药合成路线共 1 条

合成路线1

该中间体在本合成路线中的序号:(XXI)

An alternative route to (+)-lipoic acid used ethyl 4,6-di-O-acetyl-2,3-dideoxy-alpha-D-erythro-hexopyranoside (XX), prepared from triacetyl-D-glucal, as the chiral starting point. Deacetylation of (XX) with sodium methoxide under Zemplen conditions gave diol (XXI) which, after conventional benzylation, led to the 4,6-di-O-benzyl derivative (XXII). Ring opening of the cyclic acetal (XXII) with propanediol in the presence of boron trifluoride afforded the dithiane derivative (XXIII). The free hydroxyl group of (XXIII) was converted into xanthate (XXIV) by reaction with NaH and CS2, followed by methyl iodide. Reductive cleavage of the xanthate group by means of Bu3SnH and AIBN provided (XXV). Hydrolysis of the thioacetal function with HgO and BF3 provided aldehyde (XXVI). Chain homologation was performed by Wittig reaction of aldehyde (XXVI) with phosphorane (XXVII) to afford the unsaturated ester (XXVIII). Simultaneous double bond hydrogenation and benzyl ether cleavage in the presence of Raney nickel led to dihydroxy ester (XXIX). This was converted to the corresponding dimesylate (XXX), which was further cyclized to disulfide (XXXI) using the in situ generated sodium disulfide as in the precedent Schemes. Finally, basic hydrolysis of the ethyl ester (XXXI) yielded the title carboxylic acid.

1 Rao, A.V.R.; et al.; Enantiospecific synthesis of (R)-(+)-alpha-lipoic acid from D-glucose. Carbohydr Res 1986, 148, 1, 51.
中间体序号 中间体编号 品名 CAS号 分子式 供应商 用于合成
(XVI) 57956 (4S)-4,6-bis(benzyloxy)hexanal C20H24O3 详情 详情
(XX) 57950 [(2R,3S,6S)-3-(acetyloxy)-6-ethoxytetrahydro-2H-pyran-2-yl]methyl acetate C12H20O6 详情 详情
(XXI) 57951 (2R,3S,6S)-6-ethoxy-2-(hydroxymethyl)tetrahydro-2H-pyran-3-ol C8H16O4 详情 详情
(XXII) 57952 (2R,3S,6S)-3-(benzyloxy)-2-[(benzyloxy)methyl]-6-ethoxytetrahydro-2H-pyran; benzyl [(2R,3S,6S)-3-(benzyloxy)-6-ethoxytetrahydro-2H-pyran-2-yl]methyl ether C22H28O4 详情 详情
(XXIII) 57953 (2R,3S)-1,3-bis(benzyloxy)-5-(1,3-dithian-2-yl)-2-pentanol C23H30O3S2 详情 详情
(XXIV) 57954 O-[(1R,2S)-2-(benzyloxy)-1-[(benzyloxy)methyl]-4-(1,3-dithian-2-yl)butyl] S-methyl carbonodithioate C25H32O3S4 详情 详情
(XXV) 57955 benzyl (1S)-3-(benzyloxy)-1-[2-(1,3-dithian-2-yl)ethyl]propyl ether; 2-[(3S)-3,5-bis(benzyloxy)pentyl]-1,3-dithiane C23H30O2S2 详情 详情
(XXVII) 14182 ethyl 2-(triphenyl-lambda(5)-phosphanylidene)acetate; (Carbethoxymethylene)triphenylphosphorane 1099-45-2 C22H21O2P 详情 详情
(XXVIII) 57957 ethyl (E,6S)-6,8-bis(benzyloxy)-2-octenoate C24H30O4 详情 详情
(XXIX) 57958 ethyl (6S)-6,8-dihydroxyoctanoate C10H20O4 详情 详情
(XXX) 57959 ethyl (6S)-6,8-bis[(methylsulfonyl)oxy]octanoate C12H24O8S2 详情 详情
(XXXI) 57960 ethyl 5-[(3R)-1,2-dithiolan-3-yl]pentanoate C10H18O2S2 详情 详情
Extended Information