摩熵化学
数据库官网
小程序
打开微信扫一扫
首页 分子通 化学资讯 化学百科 反应查询 关于我们
请输入关键词
历史搜索
    热门化合物HOT
    • 喹啉
    • 水杨醛
    • 二溴甲烷
    • 谷胱甘肽
    • L-乳酸
    • 苯巴比妥
    • 辣椒碱
    • 非那明
    • 百草枯
    • 联苯烯
    首页 分子通 按分子结构分类 有机化合物 苯丙烷和聚酮 大环内酰胺类

    大环内酰胺类

    中文名称 英文名称 CAS号 化学式 结构式图片
    —— (9S,14S)-9,15-dimethyl-N-(2-naphthylmethyl)-11,16-dioxo-7-oxa-10,15-diazatricyclo[15.3.1.1<sup>2</sup>'<sup>6</sup>]docosa-1(21),2(22),3,5,17,19-hexaene-14-carboxamide 1460302-34-4 C33H33N3O4
    (9S,14S)-9,15-dimethyl-N-(2-naphthylmethyl)-11,16-dioxo-7-oxa-10,15-diazatricyclo[15.3.1.1<sup>2</sup>'<sup>6</sup>]docosa-1(21),2(22),3,5,17,19-hexaene-14-carboxamide
    —— (9S,14S)-9,15-dimethyl-N-(1-naphthylmethyl)-11,16-dioxo-7-oxa-10,15-diazatricyclo[15.3.1.1<sup>2</sup>'<sup>6</sup>]docosa-1(21),2(22),3,5,17,19-hexaene-14-carboxamide 1460302-17-3 C33H33N3O4
    (9S,14S)-9,15-dimethyl-N-(1-naphthylmethyl)-11,16-dioxo-7-oxa-10,15-diazatricyclo[15.3.1.1<sup>2</sup>'<sup>6</sup>]docosa-1(21),2(22),3,5,17,19-hexaene-14-carboxamide
    —— 6,7,10,11-tetrahydro-9-[(phenylmethoxy)methyl]-9H,18H-5,21:12,17-dimethenodibenzo[e,k]pyrrolo[3,4-h][1,4,13]oxadiazacyclohexadecine-18,20(19H)-dione 336883-76-2 C33H29N3O4
    6,7,10,11-tetrahydro-9-[(phenylmethoxy)methyl]-9H,18H-5,21:12,17-dimethenodibenzo[e,k]pyrrolo[3,4-h][1,4,13]oxadiazacyclohexadecine-18,20(19H)-dione
    —— (-)-(8R)-8-undecyl-1,5,9,13-tetraazacycloheptadecan-6-one 467457-44-9 C24H50N4O
    (-)-(8R)-8-undecyl-1,5,9,13-tetraazacycloheptadecan-6-one
    —— (3R,6S,9R,12R)-6-cyclopropyl-12-[(1R)-1-(4-fluorophenyl)ethyl]-3,8,9-trimethyl-2-oxa-5,8,11,14-tetrazabicyclo[16.4.0]docosa-1(22),18,20-triene-7,10,13-trione 1047666-84-1 C31H41FN4O4
    (3R,6S,9R,12R)-6-cyclopropyl-12-[(1R)-1-(4-fluorophenyl)ethyl]-3,8,9-trimethyl-2-oxa-5,8,11,14-tetrazabicyclo[16.4.0]docosa-1(22),18,20-triene-7,10,13-trione
    —— cyclo(β-HGlu(OBn))3 218943-47-6 C39H45N3O9
    cyclo(β-HGlu(OBn))3
    —— 23-benzyl-6,7,8,9,10,11,12,13,14,15-decahydro-5,25:16,21-dimethenodibenzo[m,s]-pyrrolo[3,4-p]-[1,12]diazacyclodecadecine-22,24(23H)-dione 712352-26-6 C37H37N3O2
    23-benzyl-6,7,8,9,10,11,12,13,14,15-decahydro-5,25:16,21-dimethenodibenzo[m,s]-pyrrolo[3,4-p]-[1,12]diazacyclodecadecine-22,24(23H)-dione
    —— 23-benzyl-26,27-dimethyl-6,7,8,9,10,11,12,13,14,15-decahydro-22H-5,25:16,21-dimethenodibenzo[b,h]pyrrolo[3,4-e][1,10]diazacycloicosine-22,24-dione 712352-31-3 C39H41N3O2
    23-benzyl-26,27-dimethyl-6,7,8,9,10,11,12,13,14,15-decahydro-22H-5,25:16,21-dimethenodibenzo[b,h]pyrrolo[3,4-e][1,10]diazacycloicosine-22,24-dione
    —— (3-isobutyl-7-methyl-2,5,6,9-tetraoxo-1,4,8-triazacyclotridec-10-yl)-carbamic acid benzyl ester 158221-48-8 C23H32N4O6
    (3-isobutyl-7-methyl-2,5,6,9-tetraoxo-1,4,8-triazacyclotridec-10-yl)-carbamic acid benzyl ester
    —— 5,7-etheno-13H-[1,3]dioxolo[4,5-r]pyrimido[4,5-b][6,1,10,13]benzoxatriazacyclohexadecin-13-one, 1,9,10,11,12,14,15,16-octahydro-14,15-dimethyl-22-[3-(4-morpholinyl)propoxy]-, (14S)- 1001432-02-5 C30H38N6O6
    5,7-etheno-13H-[1,3]dioxolo[4,5-r]pyrimido[4,5-b][6,1,10,13]benzoxatriazacyclohexadecin-13-one, 1,9,10,11,12,14,15,16-octahydro-14,15-dimethyl-22-[3-(4-morpholinyl)propoxy]-, (14S)-
    —— 2-((2R,6S,11S,E)-11-amino-5,12-dioxo-2-phenyl-1-oxa-4-azacyclododec-8-en-6-yl)-N-(4-chlorobenzyl)acetamide 1589555-47-4 C25H28ClN3O4
    2-((2R,6S,11S,E)-11-amino-5,12-dioxo-2-phenyl-1-oxa-4-azacyclododec-8-en-6-yl)-N-(4-chlorobenzyl)acetamide
    —— 2-((2R,6S,11S,E)-11-acetamido-5,12-dioxo-2-phenyl-1-oxa-4-azacyclododec-8-en-6-yl)-N-(4-chlorobenzyl)acetamide 1589555-34-9 C27H30ClN3O5
    2-((2R,6S,11S,E)-11-acetamido-5,12-dioxo-2-phenyl-1-oxa-4-azacyclododec-8-en-6-yl)-N-(4-chlorobenzyl)acetamide
    —— N-(4-chlorobenzyl)-2-((2R,6S,11S,E)-11-(isopropylamino)-5,12-dioxo-2-phenyl-1-oxa-4-azacyclododec-8-en-6-yl)acetamide 1395847-18-3 C28H34ClN3O4
    N-(4-chlorobenzyl)-2-((2R,6S,11S,E)-11-(isopropylamino)-5,12-dioxo-2-phenyl-1-oxa-4-azacyclododec-8-en-6-yl)acetamide
    —— 2-[2-[[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]amino]-2-oxoethoxy]acetic acid 960062-09-3 C51H49N13O11S6
    2-[2-[[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]amino]-2-oxoethoxy]acetic acid
    —— (4S,14S)-4,14-dibenzyl-2,5,13,16,21-pentazatricyclo[15.3.1.17,11]docosa-1(21),7(22),8,10,17,19-hexaene-3,15-dione 1380115-27-4 C31H31N5O2
    (4S,14S)-4,14-dibenzyl-2,5,13,16,21-pentazatricyclo[15.3.1.17,11]docosa-1(21),7(22),8,10,17,19-hexaene-3,15-dione
    —— (4R,9R,19R,24R)-3,10,14,18,25,29-hexaazapentacyclo[25.3.1.1<sup>12,16</sup>.0<sup>4,9</sup>.0<sup>19,24</sup>]dotriacontane-1(31),12(32),13,15,27,29-hexaene-2,11,17,26-tetrone 260994-32-9 C26H30N6O4
    (4R,9R,19R,24R)-3,10,14,18,25,29-hexaazapentacyclo[25.3.1.1<sup>12,16</sup>.0<sup>4,9</sup>.0<sup>19,24</sup>]dotriacontane-1(31),12(32),13,15,27,29-hexaene-2,11,17,26-tetrone
    —— 19-benzyl-16,19-dihydro-2,13-diaza<4>paracyclo<4>(3,5)pyridinophane-1,14-dione 75340-05-5 C24H25N3O2
    19-benzyl-16,19-dihydro-2,13-diaza<4>paracyclo<4>(3,5)pyridinophane-1,14-dione
    —— 6,9-dimethoxy-2,13-diaza<4>paracyclo<4>(3,5)pyridinophane-1,14-dione 81164-04-7 C19H21N3O4
    6,9-dimethoxy-2,13-diaza<4>paracyclo<4>(3,5)pyridinophane-1,14-dione
    —— 2-aminoethyl N-[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]carbamate 960062-20-8 C50H50N14O9S6
    2-aminoethyl N-[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]carbamate
    —— Ethyl 19-amino-20-nitro-11-oxo-9,16-dioxa-2,12,18,21-tetrazatricyclo[15.3.1.14,8]docosa-1(21),4(22),5,7,17,19-hexaene-2-carboxylate 1539304-83-0 C19H22N6O7
    Ethyl 19-amino-20-nitro-11-oxo-9,16-dioxa-2,12,18,21-tetrazatricyclo[15.3.1.14,8]docosa-1(21),4(22),5,7,17,19-hexaene-2-carboxylate
    —— 4-[3-carboxypropoxycarbonyl-[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]amino]butanoic acid 960062-55-9 C56H57N13O13S6
    4-[3-carboxypropoxycarbonyl-[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]amino]butanoic acid
    —— 4-hydroxy-N-[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]butanamide 960062-12-8 C51H51N13O9S6
    4-hydroxy-N-[2-[(18S,25S,35S)-35-[(S)-hydroxy(phenyl)methyl]-28-(methoxymethyl)-21-methyl-18-[2-(methylamino)-2-oxoethyl]-16,23,30,33-tetraoxo-25-propan-2-yl-3,13,20,27,37-pentathia-7,17,24,31,34,39,40,41,42,43-decazaheptacyclo[34.2.1.12,5.112,15.119,22.126,29.06,11]tritetraconta-1(38),2(43),4,6(11),7,9,12(42),14,19(41),21,26(40),28,36(39)-tridecaen-8-yl]-1,3-thiazol-4-yl]butanamide
    —— 29-iodo-1,14,33,-triaza-17,20,23-trioxatricyclo[12.11.7.1<sup>27,31</sup>]tritriaconta-27(33),28,30-triene-2,13-dione 506424-17-5 C27H42IN3O5
    29-iodo-1,14,33,-triaza-17,20,23-trioxatricyclo[12.11.7.1<sup>27,31</sup>]tritriaconta-27(33),28,30-triene-2,13-dione
    —— spiro[N-methyl-piperidine-3,4-piperazinorifamycin S] 871115-16-1 C44H58N4O11
    spiro[N-methyl-piperidine-3,4-piperazinorifamycin S]
    —— N-nitro-12-dodecanelactam 91083-89-5 C12H22N2O3
    N-nitro-12-dodecanelactam
    —— N-nitroso-12-dodecanelactam 91083-88-4 C12H22N2O2
    N-nitroso-12-dodecanelactam
    —— benzyl N-[(4S,6S,10S)-6-amino-13-methyl-9,14-dioxo-2-oxa-8,13-diazatricyclo[13.3.1.0<sup>4,8</sup>]nonadeca-1(19),15,17-trien-10-yl]carbamate 1264222-46-9 C25H30N4O5
    benzyl N-[(4S,6S,10S)-6-amino-13-methyl-9,14-dioxo-2-oxa-8,13-diazatricyclo[13.3.1.0<sup>4,8</sup>]nonadeca-1(19),15,17-trien-10-yl]carbamate
    —— 4-amino-20-ethoxy-22-methyl-13-oxa-7-thia-3,5,17-triazatetracyclo[17.3.1.1(2,6).1(8,12)]pentacosa-1(22),2(24),3,5,8(25),9,11,19(23),20-nonaen-18-one 1052646-49-7 C23H24N4O3S
    4-amino-20-ethoxy-22-methyl-13-oxa-7-thia-3,5,17-triazatetracyclo[17.3.1.1(2,6).1(8,12)]pentacosa-1(22),2(24),3,5,8(25),9,11,19(23),20-nonaen-18-one
    —— 27-Cyclohexyl-21-methoxy-15-methyl-9,9-dioxo-10-propan-2-yl-9lambda6-thia-1,8,10,15-tetrazapentacyclo[15.8.1.12,6.13,25.019,24]octacosa-2,4,6(28),17,19(24),20,22,25(27)-octaene-7,16-dione 1204417-23-1 C34H42N4O5S
    27-Cyclohexyl-21-methoxy-15-methyl-9,9-dioxo-10-propan-2-yl-9lambda6-thia-1,8,10,15-tetrazapentacyclo[15.8.1.12,6.13,25.019,24]octacosa-2,4,6(28),17,19(24),20,22,25(27)-octaene-7,16-dione
    —— incednine aglycon 1009805-53-1 C29H39NO4
    incednine aglycon
    —— rifamycin B(2-) 13929-35-6 C39H47NO14-2
    rifamycin B(2-)
    —— 3,15,21-triaza-4,5:13,14-dibenzo-6,12-dioxa-9-thiabicyclo[15.3.1]heneicosa-1(21),17,19-triene-2,16-dione 128373-44-4 C23H21N3O4S
    3,15,21-triaza-4,5:13,14-dibenzo-6,12-dioxa-9-thiabicyclo[15.3.1]heneicosa-1(21),17,19-triene-2,16-dione
    —— 6,12-dioxo-1,5,13,17,22-penta-azatricyclo-<15.2.2.1<sup>7,11</sup>>docosa-7(22),8,10-triene 54945-23-2 C17H25N5O2
    6,12-dioxo-1,5,13,17,22-penta-azatricyclo-<15.2.2.1<sup>7,11</sup>>docosa-7(22),8,10-triene
    —— 1,5,9,13,16,20,24,28-Octazatricyclo[26.2.2.213,16]tetratriacontane-6,8,21,23-tetrone 133116-72-0 C26H48N8O4
    1,5,9,13,16,20,24,28-Octazatricyclo[26.2.2.213,16]tetratriacontane-6,8,21,23-tetrone
    —— 3'-N-(benzylthiocarbamoyl)-3'-N-demethyl-6-O-methyl-9a-aza-9a-homoerythromycin A 1192304-57-6 C45H75N3O13S
    3'-N-(benzylthiocarbamoyl)-3'-N-demethyl-6-O-methyl-9a-aza-9a-homoerythromycin A
    —— 15,19b-dihydro-19b-hydroxy<1,4,7>trioxa<10>thia<13>azacyclopentadecano<12,13-a>isoindol-15-one 74359-70-9 C17H23NO5S
    15,19b-dihydro-19b-hydroxy<1,4,7>trioxa<10>thia<13>azacyclopentadecano<12,13-a>isoindol-15-one
    —— 2'-O,3'-N-(carbonimidoyl)-3'-N-demethyl-N'-[3-(methyloxy)propyl]-6-O-methyl-9a-aza-9a-homoerythromycin A 1192304-31-6 C42H75N3O14
    2'-O,3'-N-(carbonimidoyl)-3'-N-demethyl-N'-[3-(methyloxy)propyl]-6-O-methyl-9a-aza-9a-homoerythromycin A
    —— 4-(2-nitrobenzenesulfonyl)-4,7,17-triazabicyclo[11.3.1]heptadeca-1(17),13,15-trien-6-one 404034-84-0 C20H24N4O5S
    4-(2-nitrobenzenesulfonyl)-4,7,17-triazabicyclo[11.3.1]heptadeca-1(17),13,15-trien-6-one
    —— 2-methyl-N-[9-[2-[7-[2-[2-(2-methylpropanoylamino)-6-oxo-1H-purin-9-yl]acetyl]-3,9-dioxo-1,4,7,10-tetrazacyclododec-1-yl]-2-oxoethyl]-6-oxo-1H-purin-2-yl]propanamide 289684-64-6 C30H38N14O8
    2-methyl-N-[9-[2-[7-[2-[2-(2-methylpropanoylamino)-6-oxo-1H-purin-9-yl]acetyl]-3,9-dioxo-1,4,7,10-tetrazacyclododec-1-yl]-2-oxoethyl]-6-oxo-1H-purin-2-yl]propanamide
    —— N-[9-[2-(3,9-dioxo-1,4,7,10-tetrazacyclododec-1-yl)-2-oxoethyl]-6-oxo-1H-purin-2-yl]-2-methylpropanamide 289684-63-5 C19H27N9O5
    N-[9-[2-(3,9-dioxo-1,4,7,10-tetrazacyclododec-1-yl)-2-oxoethyl]-6-oxo-1H-purin-2-yl]-2-methylpropanamide
    —— (S)-5,9-bis[(4-methylphenyl)sulfonyl]-4-phenyl-1,5,9-triazacyclotridecan-2-one 422565-32-0 C30H37N3O5S2
    (S)-5,9-bis[(4-methylphenyl)sulfonyl]-4-phenyl-1,5,9-triazacyclotridecan-2-one
    —— (S)-4-phenyl-1,5,9-triazacyclotridecan-2-one 126641-91-6 C16H25N3O
    (S)-4-phenyl-1,5,9-triazacyclotridecan-2-one
    —— (S)-4-phenyl-9-(3-phenylprop-2-enoyl)-1,5,9-triazacyclotridecan-2-one 65094-32-8 C25H31N3O2
    (S)-4-phenyl-9-(3-phenylprop-2-enoyl)-1,5,9-triazacyclotridecan-2-one
    —— 2,2',2''-(1,3,8,10,15,17-hexaoxo-5,6,12,13,19,20-hexadehydro-8,10,15,17-tetrahydro-1H-cyclododeca[1,12-f:4,5-f':8,9-f'']triisoindole-2,9,16(3H)-triyl)triacetic acid 1352007-54-5 C36H15N3O12
    2,2',2''-(1,3,8,10,15,17-hexaoxo-5,6,12,13,19,20-hexadehydro-8,10,15,17-tetrahydro-1H-cyclododeca[1,12-f:4,5-f':8,9-f'']triisoindole-2,9,16(3H)-triyl)triacetic acid
    —— tri-tert-butyl 2,2',2''-(1,3,8,10,15,17-hexaoxo-5,6,12,13,19,20-hexadehydro-8,10,15,17-tetrahydro-1H-cyclododeca[1,12-f:4,5-f':8,9-f'']triisoindole-2,9,16(3H)-triyl)triacetate 1352007-60-3 C48H39N3O12
    tri-tert-butyl 2,2',2''-(1,3,8,10,15,17-hexaoxo-5,6,12,13,19,20-hexadehydro-8,10,15,17-tetrahydro-1H-cyclododeca[1,12-f:4,5-f':8,9-f'']triisoindole-2,9,16(3H)-triyl)triacetate
    —— 1,14-diazabicyclo<10.5.1>octadecan-18-one 99014-82-1 C16H30N2O
    1,14-diazabicyclo<10.5.1>octadecan-18-one
    —— (4S,20E)-26-hydroxy-24-methoxy-4-methyl-3-oxa-9,17-diazabicyclo[20.4.0]hexacosa-1(22),20,23,25-tetraene-2,8,18-trione 1200112-12-4 C25H36N2O6
    (4S,20E)-26-hydroxy-24-methoxy-4-methyl-3-oxa-9,17-diazabicyclo[20.4.0]hexacosa-1(22),20,23,25-tetraene-2,8,18-trione
    —— 4-[2-(5-Methyl-2,4-dioxopyrimidin-1-yl)acetyl]-1,4,7,10-tetrazacyclododecane-2,8-dione 289684-55-5 C15H22N6O5
    4-[2-(5-Methyl-2,4-dioxopyrimidin-1-yl)acetyl]-1,4,7,10-tetrazacyclododecane-2,8-dione
    —— 3'-(3-nitrophenyl)-4'H-3,11-diazaspiro[bicyclo[11.3.1]heptadeca[1(17),13,15]triene-5,5'-isoxazole]-4,6,10-trione 1325731-30-3 C23H22N4O6
    3'-(3-nitrophenyl)-4'H-3,11-diazaspiro[bicyclo[11.3.1]heptadeca[1(17),13,15]triene-5,5'-isoxazole]-4,6,10-trione
    —— 14-(Prop-2-enoxymethyl)-1,4,7,13,16-pentaoxa-10,19-diazacyclohenicosane-11,18-dione 107106-42-3 C18H32N2O8
    14-(Prop-2-enoxymethyl)-1,4,7,13,16-pentaoxa-10,19-diazacyclohenicosane-11,18-dione