MY8700745A - 6(r)-(2-8-acyloxy-2'-methyl-6'methyl(or hydrogen)-polyhydronapthyl-1')-ethyl)-4(r)-hydroxy-3,4,5,6-tetrahydro-24-pyran-2-ones, the hydroxy acid from of said pyranones, the parmaceutically acceptable satls of said hydroxy acids, and the lower alkyl, and phenyl, dimethylamino or acetylamino substituted lower alkyl esters of said hydroxy acid, processes for preparing the same, and a parmaceutical antihypercholesterolemic composition containing the same. - Google Patents

6(r)-(2-8-acyloxy-2'-methyl-6'methyl(or hydrogen)-polyhydronapthyl-1')-ethyl)-4(r)-hydroxy-3,4,5,6-tetrahydro-24-pyran-2-ones, the hydroxy acid from of said pyranones, the parmaceutically acceptable satls of said hydroxy acids, and the lower alkyl, and phenyl, dimethylamino or acetylamino substituted lower alkyl esters of said hydroxy acid, processes for preparing the same, and a parmaceutical antihypercholesterolemic composition containing the same.

Info

Publication number
MY8700745A
MY8700745A MY745/87A MY8700745A MY8700745A MY 8700745 A MY8700745 A MY 8700745A MY 745/87 A MY745/87 A MY 745/87A MY 8700745 A MY8700745 A MY 8700745A MY 8700745 A MY8700745 A MY 8700745A
Authority
MY
Malaysia
Prior art keywords
hydroxy
methyl
lower alkyl
same
hydroxy acid
Prior art date
Application number
MY745/87A
Other languages
English (en)
Inventor
Alvin K William
Robert L Smith
William F Hoffmann
Original Assignee
Merck & Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=27494171&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=MY8700745(A) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from US06/175,232 external-priority patent/US4293496A/en
Application filed by Merck & Co Inc filed Critical Merck & Co Inc
Publication of MY8700745A publication Critical patent/MY8700745A/xx

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D309/00—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings
    • C07D309/16—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
    • C07D309/28—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
    • C07D309/30—Oxygen atoms, e.g. delta-lactones
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P3/00—Drugs for disorders of the metabolism
    • A61P3/06—Antihyperlipidemics

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Obesity (AREA)
  • Diabetes (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Engineering & Computer Science (AREA)
  • Hematology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Pyrane Compounds (AREA)
  • Steroid Compounds (AREA)
MY745/87A 1980-02-04 1987-12-30 6(r)-(2-8-acyloxy-2'-methyl-6'methyl(or hydrogen)-polyhydronapthyl-1')-ethyl)-4(r)-hydroxy-3,4,5,6-tetrahydro-24-pyran-2-ones, the hydroxy acid from of said pyranones, the parmaceutically acceptable satls of said hydroxy acids, and the lower alkyl, and phenyl, dimethylamino or acetylamino substituted lower alkyl esters of said hydroxy acid, processes for preparing the same, and a parmaceutical antihypercholesterolemic composition containing the same. MY8700745A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US11805180A 1980-02-04 1980-02-04
US11804980A 1980-02-04 1980-02-04
US17546080A 1980-08-05 1980-08-05
US06/175,232 US4293496A (en) 1980-02-04 1980-08-05 6(R)-[2-(8-Hydroxy-2,6-dimethylpolyhydronaphthyl-1)-ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-ones

Publications (1)

Publication Number Publication Date
MY8700745A true MY8700745A (en) 1987-12-31

Family

ID=27494171

Family Applications (1)

Application Number Title Priority Date Filing Date
MY745/87A MY8700745A (en) 1980-02-04 1987-12-30 6(r)-(2-8-acyloxy-2'-methyl-6'methyl(or hydrogen)-polyhydronapthyl-1')-ethyl)-4(r)-hydroxy-3,4,5,6-tetrahydro-24-pyran-2-ones, the hydroxy acid from of said pyranones, the parmaceutically acceptable satls of said hydroxy acids, and the lower alkyl, and phenyl, dimethylamino or acetylamino substituted lower alkyl esters of said hydroxy acid, processes for preparing the same, and a parmaceutical antihypercholesterolemic composition containing the same.

Country Status (22)

Country Link
EP (1) EP0033538B1 (es)
AU (1) AU548996B2 (es)
CA (1) CA1199322A (es)
CY (1) CY1404A (es)
DD (1) DD155989A5 (es)
DE (1) DE3173042D1 (es)
DK (1) DK157292C (es)
ES (1) ES499079A0 (es)
FI (1) FI78082C (es)
GR (1) GR74798B (es)
HK (1) HK16488A (es)
IE (1) IE51478B1 (es)
IL (1) IL62044A (es)
MA (1) MA19054A1 (es)
MY (1) MY8700745A (es)
NL (1) NL930009I2 (es)
NO (2) NO154229C (es)
NZ (1) NZ196172A (es)
PT (1) PT72441B (es)
RO (1) RO82367B (es)
SG (1) SG61087G (es)
YU (1) YU28181A (es)

Families Citing this family (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0692381B2 (ja) * 1980-03-31 1994-11-16 三共株式会社 Ｍｂ−５３０ａ誘導体
US4343814A (en) * 1980-11-17 1982-08-10 Merck & Co., Inc. Hypocholesterolemic fermentation products
US4432996A (en) * 1980-11-17 1984-02-21 Merck & Co., Inc. Hypocholesterolemic fermentation products and process of preparation
EP0094443A1 (en) * 1982-05-17 1983-11-23 Merck & Co. Inc. 6(R)-(2-(8(S) (2,2-dimethylbutyryloxy)-2(S),6(S)-dimethyl-1,2,3,4,4a(S),5,6,7,8,8a(S)-decahydronaphthyl-1(S))ethyl)-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one, process for preparing and pharmaceutical composition containing the same
US4503072A (en) * 1982-12-22 1985-03-05 Merck & Co., Inc. Antihypercholesterolemic compounds
EP0117228B1 (en) * 1983-01-24 1986-11-05 Sandoz Ag Analogs of mevalonolactone and derivatives thereof, processes for their production, pharmaceutical compositions containing them and their use as pharmaceuticals
DE3480923D1 (de) * 1983-10-11 1990-02-08 Merck & Co Inc Verfahren zur c-methylierung von 2-methylbutyraten.
EP0137444B1 (en) * 1983-10-11 1990-01-31 Merck & Co. Inc. Processes for preparing 6(R)-[2-[8(S)(2,2-dimethylbutyryloxy)-2(S),6(S)-dimethyl-1,2,3,4,4a(S),5,6,7,8,8a(S)-Decahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one
US4668699A (en) * 1985-08-05 1987-05-26 Merck & Co., Inc. Novel HMG-CoA reductase inhibitors
US4833258A (en) * 1987-02-17 1989-05-23 Merck & Co., Inc. Intermediates useful in the preparation of HMG-COA reductase inhibitors
US4997848A (en) 1987-10-27 1991-03-05 Sankyo Company, Limited Octahydronaphthalene oxime derivatives for cholesterol synthesis inhibition
US5021451A (en) * 1988-11-14 1991-06-04 Hoffman-La Roche Inc. Method for inhibiting hyperproliferative diseases
GB8915280D0 (en) * 1989-07-04 1989-08-23 British Bio Technology Compounds
US5110825A (en) * 1989-12-28 1992-05-05 Shionogi & Co., Ltd. Benzofuran derivative
GB9100174D0 (en) * 1991-01-04 1991-02-20 British Bio Technology Compounds
NZ250609A (en) * 1992-12-28 1995-07-26 Sankyo Co Hexahydronaphthalene esters and ring closed lactones; preparation and medicaments
US6642268B2 (en) 1994-09-13 2003-11-04 G.D. Searle & Co. Combination therapy employing ileal bile acid transport inhibiting benzothipines and HMG Co-A reductase inhibitors
US6268392B1 (en) 1994-09-13 2001-07-31 G. D. Searle & Co. Combination therapy employing ileal bile acid transport inhibiting benzothiepines and HMG Co-A reductase inhibitors
NZ286920A (en) * 1995-07-03 1997-06-24 Sankyo Co Use of combination of hmg-coa reductase inhibitors and of insulin sensitizers for the prevention/treatment of arteriosclerosis or xanthoma
ES2131037T3 (es) * 1995-12-06 2001-12-16 Balkanpharma Razgrad Ad Procedimiento de preparacion de lovastatina.
CA2185961A1 (en) 1996-09-19 1998-03-20 K.S. Keshava Murthy Process for producing simvastatin
US6083497A (en) 1997-11-05 2000-07-04 Geltex Pharmaceuticals, Inc. Method for treating hypercholesterolemia with unsubstituted polydiallylamine polymers
SI9800057A (sl) * 1998-02-26 1999-08-31 Krka, Tovarna Zdravil, D.D. Postopek za pripravo simvastatina in njegovih derivatov
CA2240983A1 (en) 1998-06-18 1999-12-18 Yong Tao Process to manufacture simvastatin and intermediates
DK1140189T3 (da) 1998-12-23 2003-09-15 Searle Llc Kombinationer af ileal galdesyre-transportinhibitorer og fibrinsyrederivater til cardiovaskulære indikationer
BR9916486A (pt) 1998-12-23 2002-02-05 Searle Llc Combinações de inibidores do transporte de ácidos biliares no ìleo e inibidores da proteìna de transferência do ester colesteril para indicações cardiovasculares
AU2157500A (en) 1998-12-23 2000-07-31 G.D. Searle Llc Combinations of cholesteryl ester transfer protein inhibitors and bile acid sequestering agents for cardiovascular indications
EA004877B1 (ru) 1998-12-23 2004-08-26 Джи.Ди.Сирл Ллс Сочетания ингибиторов транспорта желчных кислот в подвздошной кишке и агентов, секвестрирующих желчные кислоты, для сердечно-сосудистых показаний
US6458850B1 (en) 1998-12-23 2002-10-01 G.D. Searle, Llc Combinations of cholesteryl ester transfer protein inhibitors and fibric acid derivatives for cardiovascular indications
AU2157400A (en) 1998-12-23 2000-07-31 G.D. Searle & Co. Combinations of cholesteryl ester transfer protein inhibitors and hmg coa reductase inhibitors for cardiovascular indications
AU3103800A (en) 1998-12-23 2000-07-31 G.D. Searle Llc Combinations of cholesteryl ester transfer protein inhibitors and nicotinic acidderivatives for cardiovascular indications
EP1286984A2 (en) 2000-03-10 2003-03-05 Pharmacia Corporation Method for the preparation of tetrahydrobenzothiepines
ES2329974T3 (es) * 2000-09-07 2009-12-03 Kaneka Corporation Metodos para la cristalizacion de acidos hidroxicarboxilicos.
BR0213501A (pt) 2001-11-02 2004-08-24 Searle Llc Compostos de benzotiepina mono- e di-fluorada como inibidores de transporte de ácido biliar co-dependente de sódio apical (asbt) e captação de taurocolato
MXPA04006255A (es) 2002-01-17 2004-09-27 Pharmacia Corp Compuestos novedosos de alquil/aril hidroxi o ceto tiepina como inhibidores del transporte del acido biliar codependiente del sodio apical y la captacion de taurocolato.
SI21187A (sl) 2002-03-26 2003-10-31 Krka, Tovarna Zdravil D.D., Novo Mesto Postopek za pripravo 4-oksitetrahidropiran-2-onov
KR20040092790A (ko) * 2003-04-29 2004-11-04 씨제이 주식회사 심바스타틴 중간체 제조방법
EP1741427A1 (en) 2005-07-06 2007-01-10 KRKA, D.D., Novo Mesto Pharmaceutical composition comprising simvastatin and ezetimibe
PT2359826E (pt) 2006-07-05 2014-01-20 Takeda Gmbh Combinação de um inibidor da hmg-coa redutase rosuvastatina e um inibidor da fosfodiesterase 4, tais como roflumilaste, óxido de n-roflumilaste, para o tratamento de doenças pulmonares inflamatórias
WO2009013764A2 (en) * 2007-07-24 2009-01-29 Jubilant Organosys Limited Process for producing 6(r)-[2-(8'(s)-2 ',2 '-dimethylbutyryloxy-2'(s),6'(r)-dimethyl-1,2,6,7', 8',8a'(r)- hexahydronaphthyl-l'(s))ethyl]-4(r)-hydroxy-3,4,5,6- tetrahydro-2h-pyran-2-one
JOP20080381B1 (ar) 2007-08-23 2023-03-28 Amgen Inc بروتينات مرتبطة بمولدات مضادات تتفاعل مع بروبروتين كونفيرتاز سيتيليزين ككسين من النوع 9 (pcsk9)
ES2330184B1 (es) 2008-06-03 2010-07-05 Neuron Biopharma, S.A. Uso de estatinas como anticonvulsivantes, antiepilepticos y neuroprotectores.
ES2343049B1 (es) 2008-10-15 2011-06-10 Neuron Biopharma, S.A. Biosintesis de derivados de monacolina j.
EP2204170A1 (en) 2008-12-01 2010-07-07 LEK Pharmaceuticals D.D. Pharmaceutical composition comprising ezetimibe and simvastatin
WO2010069593A1 (en) 2008-12-19 2010-06-24 Krka, D. D., Novo Mesto Use of amphiphilic compounds for controlled crystallization of statins and statin intermediates
EP2327682A1 (en) 2009-10-29 2011-06-01 KRKA, D.D., Novo Mesto Use of amphiphilic compounds for controlled crystallization of statins and statin intermediates
EP2216016A1 (en) 2009-02-06 2010-08-11 LEK Pharmaceuticals d.d. Process for the preparation of a pharmaceutical composition comprising ezetimibe
EP2241561A1 (en) * 2009-04-16 2010-10-20 Neuron Biopharma, S.A. Neuroprotective, hypocholesterolemic and antiepileptic compound
WO2011002424A2 (en) 2009-07-02 2011-01-06 Bilgic Mahmut Solubility and stability enchancing pharmaceutical formulation
AR079336A1 (es) 2009-12-11 2012-01-18 Irm Llc Antagonistas de la pro-proteina convertasa-subtilisina/quexina tipo 9 (pcsk9)
EP2368543A1 (en) 2010-03-25 2011-09-28 KRKA, tovarna zdravil, d.d., Novo mesto Method of preparing a granulated pharmaceutical composition comprising simvastatin and/or ezetimibe
ES2380473B1 (es) * 2010-10-13 2013-02-19 Neuron Biopharma, S.A. Compuesto neuroprotector, hipocolesterolémico, antiinflamatorio y antiepiléptico.
JOP20200043A1 (ar) 2011-05-10 2017-06-16 Amgen Inc طرق معالجة أو منع الاضطرابات المختصة بالكوليسترول
CA2865796A1 (en) 2011-12-29 2013-07-04 Trustees Of Tufts College Functionalization of biomaterials to control regeneration and inflammation responses
EA039663B1 (ru) 2012-05-03 2022-02-24 Амген Инк. Применение антитела против pcsk9 для снижения сывороточного холестерина лпнп и лечения связанных с холестерином расстройств
AR091462A1 (es) 2012-06-15 2015-02-04 Genentech Inc Anticuerpos anti-pcsk9, formulaciones, dosificacion y metodos de uso

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5612114B2 (es) * 1974-06-07 1981-03-18
US4049495A (en) 1974-06-07 1977-09-20 Sankyo Company Limited Physiologically active substances and fermentative process for producing the same
US4137322A (en) 1976-11-02 1979-01-30 Sankyo Company Limited ML-236B carboxylic acid derivatives and their use as antihyperlipemic agents
JPS6026094B2 (ja) 1978-07-04 1985-06-21 三共株式会社 テトラヒドロｍｌ↓−２３６ｂおよびその誘導体並びにそれを有効成分とする高脂血症治療剤
JPS5925599B2 (ja) * 1979-02-20 1984-06-19 三共株式会社 新生理活性物質モナコリンｋおよびその製造法
AU535944B2 (en) * 1979-06-15 1984-04-12 Merck & Co., Inc. Hypocholestermic fermentation products from aspergillus
US4231938A (en) 1979-06-15 1980-11-04 Merck & Co., Inc. Hypocholesteremic fermentation products and process of preparation
PT72394B (en) 1980-02-04 1982-09-06 Merck & Co Inc Process for preparing dihydro and tetrahydromevinoline hypocholesterolimics

Also Published As

Publication number Publication date
AU548996B2 (en) 1986-01-09
NO154229B (no) 1986-05-05
DE3173042D1 (en) 1986-01-09
NO810358L (no) 1981-08-05
ES8609296A1 (es) 1985-10-16
CA1199322A (en) 1986-01-14
AU6657381A (en) 1981-08-13
RO82367A (ro) 1984-02-21
IL62044A0 (en) 1981-03-31
NO154229C (no) 1986-08-13
DD155989A5 (de) 1982-07-21
IE810204L (en) 1981-08-04
ES499079A0 (es) 1985-10-16
PT72441B (pt) 1984-08-01
IL62044A (en) 1987-03-31
FI78082C (fi) 1989-06-12
NL930009I1 (nl) 1993-04-01
NO1994001I1 (no) 1994-07-01
FI810287L (fi) 1981-08-05
PT72441A (pt) 1981-03-01
HK16488A (en) 1988-03-11
SG61087G (en) 1987-10-23
RO82367B (ro) 1984-02-28
NZ196172A (en) 1985-01-31
EP0033538A2 (en) 1981-08-12
DK157292C (da) 1990-05-07
IE51478B1 (en) 1987-01-07
EP0033538A3 (en) 1982-02-24
CY1404A (en) 1988-04-22
DK46181A (da) 1981-08-05
DK157292B (da) 1989-12-04
FI78082B (fi) 1989-02-28
YU28181A (en) 1983-10-31
NL930009I2 (nl) 1993-09-16
GR74798B (es) 1984-07-12
MA19054A1 (fr) 1981-10-01
EP0033538B1 (en) 1985-11-27

Similar Documents

Publication Publication Date Title
DE3173042D1 (en) 6(r)-(2-(8'-acyloxy-2'-methyl-6'-methyl (or hydrogen)-polyhydronaphthyl-1')-ethyl)-4(r)-hydroxy-3,4,5,6-tetrahydro-2h-pyran-2-ones, the hydroxy acid form of said pyranones, the pharmaceutically acceptable salts of said hydroxy acids, and the lower alkyl, and phenyl, dimethylamino or acetylamino substituted lower alkyl esters of said hydroxy acid, processes for preparing the same, and a pharmaceutical antihypercholesterolemic composition containing the same
EP0033536A3 (en) 6(r)-(2-(8'-etherified-hydroxy-2',6'-dimethylpolyhydro-naphthyl-1')-ethyl)-4(r)-hydroxy-3,4,5,6-tetrahydro-2h-pyran-2-ones, the hydroxy acid form of said pyranones, the salts and esters of said acid form, process for preparing the same and an antihypercholesterolemic pharmaceutical composition containing the same
AU664663B2 (en) Compounds useful as sweetening agents and process for their preparation
JPS549269A (en) Carboxylic acid esters, process for their preparation and insecticides and miticides containing the same as active constituents
ZA983047B (en) An oleonsin 5' regulatory region for the modification of plant seed lipid composition
EP0582931A3 (en) Process for the continuous preparation of diarylcarbonates from dialkylcarbonates
HUT47376A (en) Insecticide compositions containing /p-phenoxy-phenoxy/-methyl-heteroaromatic compounds as active components and process for producing the active components
AU3711893A (en) Liquid compositions containing carboxylic esters
EP0484769A3 (en) Improved process for crystallizing l-alpha-aspartyl-l-phenylalanine methyl ester from the solution
AU646436B2 (en) Processes for preparing 2-halogeno-3-hydroxy-3- phenylpropionic acid ester compounds
KE3746A (en) 6(r)-(2-(8'-acyloxy-2'-methyl-6'-methyl(or hydrogen)-polyhydronaphthyl-1')-ethyl)-4(r)-hydroxy-3,4,5,6-tetrahydro-2h-pyran-2-ones,the hydroxy acid form of said pyranones,the pharmaceutically acceptable salts of said hydroxy acids,and the lower alkyl,and phenyl,dimethylamino or acetylamino substituted lower alkyl esters of said hydroxy acid,processes for preparing the same, and a pharmaceutical antihypercholesterolemic composition containing the same
IL101719A (en) Liquid refrigerant compositions containing complex carboxylic esters as lubricant
EP0137444A3 (en) Processes for preparing 6(r)-û2-û8(s)(2,2-dimethylbutyryloxy)-2(s),6(s)-dimethyl-1,2,3,4,4a(s),5,6,7,8,8a(s)-decahydronaphthyl-1(s)¨ethyl¨-4(r)-hydroxy-3,4,5,6-tetrahydro-2h-pyran-2-one
EP0558012A3 (en) Method for the manufacture of branched polysiloxane
ITMI921784A1 (it) Procedimento per l'allontanamento dei componenti volatili da soluzioni contenenti polifenileneteri
BE873083A (fr) Procede de reduction d'inflammabilite d'un jet de pulverisation obtenu a partir d'un recipient pressurise
EP0560158A3 (en) Process for the preparation of beta-aminoacrylic acid esters
CA2097784A1 (en) Alloy for After-Fabrication Hot-Dip Galvanizing
DE3362750D1 (en) Process for preparing alpha,omega-bis(2-chlorophenoxy)-alkane-4,4'-dicarboxylic acid or its lower alkyl ester
EP0473020A3 (en) Process for the preparation of alkali metal salts of 2-phosphonobutane-1,2,4-tricarboxylic acid
JPS55145664A (en) Dihydroindole derivative
JPS5386034A (en) Insecticides and miticides containing novel cyclopropanecarboxylic acid esters and process for their preparation
PL267947A1 (en) Method for removal of unsaturated compounds from 1,2-dichlorethane
RO84747B (ro) Compozitie lichida pentru reglarea cresterii plantelor
IL105528A0 (en) Liquid compositions containing carboxylic esters