References
1a
Otera J.
Chem. Rev.
1993,
93:
1449
1b
Otera J.
Angew. Chem. Int. Ed.
2001,
40:
2044
2
Otera J.
Esterification
Wiley-VCH;
Weinheim:
2003.
3
Ishihara K.
Ohara S.
Yamamoto H.
Science
2000,
290:
1140
4
Wakasugi K.
Misaki T.
Yamada K.
Tanabe Y.
Tetrahedron Lett.
2000,
41:
5249
5
Goossen LS.
Paetzold J.
Angew. Chem. Int. Ed.
2002,
41:
1237
6
Xiang J.
Orita A.
Otera J.
Angew. Chem. Int. Ed.
2002,
41:
4117
7
Trujillo JI.
Gopalan AS.
Tetrahedron Lett.
1993,
34:
7355
8
Lee JC.
Song I.-G.
Park JY.
Synth. Commun.
2002,
32:
2209
9
Neises B.
Steglich W.
Angew. Chem. Int. Ed. Engl.
1978,
17:
522
10
Höfle G.
Steglich W.
Vorbrüggen H.
Angew. Chem. Int. Ed. Engl.
1978,
17:
569
11
Seyferth D.
Menzel H.
Dow AW.
Flood TC.
J. Organomet. Chem.
1972,
44:
279
12
Podlech J.
J. Prakt. Chem.
1998,
340:
679
13
Eistert B.
Regitz M.
Heck G.
Schwall H.
In Houben-Weyl
4th ed., Vol. X/4:
Müller E.
Thieme;
Stuttgart:
1968.
p.473-893
14
Meerwein H.
Florian W.
Schön N.
Stopp G.
Justus Liebigs Ann. Chem.
1961,
641:
1
15
Bredereck H.
Effenberger F.
Simchen G.
Chem. Ber.
1963,
96:
1350
16
Bredereck H.
Simchen G.
Rebsdat S.
Kantlehner W.
Horn P.
Wahl R.
Hoffmann H.
Grieshaber P.
Chem. Ber.
1968,
101:
41
17
Arnold Z.
Kornilov M.
Collect. Czech. Chem. Commun.
1964,
29:
645
18
Mohacsi E.
Synth. Commun.
1983,
13:
723
19
Baldwin JE.
Rudolph M.
Tetrahedron Lett.
1994,
35:
6163
20 Winberg HE. inventors; US 3239519.
; Chem. Abstr. 1966, 64, 15854
21
Theisen P.
McCollum C.
Andrus A.
Nucleosides Nucleotides
1993,
12:
1033
22
Bredereck H.
Effenberger F.
Botsch H.
Chem. Ber.
1964,
97:
3397
23
Simchen G.
Hoffmann H.
Bredereck H.
Chem. Ber.
1968,
101:
51
24
Bredereck H.
Simchen G.
Wahl R.
Chem. Ber.
1968,
101:
4048
25
Bredereck H.
Simchen G.
Funke B.
Chem. Ber.
1971,
104:
2709
26
Bredereck H.
Simchen G.
Horn P.
Chem. Ber.
1970,
103:
210
27 inventors; JP 55118452.
; Chem. Abstr. ???, 95, 6861
28
Zemlicka J.
Collect. Czech. Chem. Commun.
1963,
28:
1060
29
Zemlicka J.
Collect. Czech. Chem. Commun.
1970,
35:
3575
30
Wrobel J.
Millen J.
Sredy J.
Dietrich A.
Kelly JM.
J. Med. Chem.
1989,
32:
2493
31
Anelli PL.
Brocchetta M.
Palano D.
Visigalli M.
Tetrahedron Lett.
1997,
38:
2367
32
Holtwick JB.
Golankiewicz B.
Holmes BN.
Leonard NJ.
J. Org. Chem.
1979,
44:
3835
33
Helfer DL.
Hosmane RS.
Leonard NL.
J. Org. Chem.
1981,
46:
4803
34
Hosmane RS.
Leonard NJ.
Synthesis
1981,
118
35
Gloede J.
Haase L.
Groß H.
Z. Chem.
1969,
201
36
Granik VG.
Zhidkova AM.
Glushkov RG.
Russ. Chem. Rev. (Engl. Transl.)
1977,
46:
361
37
Abdullah RF.
Brinkmeyer RS.
Tetrahedron
1979,
35:
1675
38
Brechbühler H.
Büchi H.
Hatz E.
Schreiber J.
Eschenmoser A.
Angew. Chem. Int. Ed. Engl.
1963,
2:
212 ; Angew. Chem. 1963, 75, 296
39
Vorbrüggen H.
Angew. Chem.
1963,
75:
296
40
Brechbühler H.
Büchi H.
Hatz E.
Schreiber J.
Eschenmoser A.
Helv. Chim. Acta
1965,
48:
1746
41a
Vorbrüggen H.
Justus Liebigs Ann. Chem.
1974,
821
41b While at Stanford in 1962 as a postdoc with C. Djerassi, I read with great interest the seminal publication of H. Meerwein et al. (see ref. 14) on the syntheses and reactions of new amide acetals and I was intrigued by the observation that on addition of water to cyclic DMF ethylene acetal 7g, heat was evolved. To test whether 7g might be an interesting new reagent for mild selective ketalizations of carbonyl groups, I prepared DMF diethyl acetal 7b and converted it with ethylene glycol into DMF ethylene acetal 7g. Yet, cholestan-3-one only reacted with 7g in boiling CH2Cl2 after adding acetic acid as a catalyst, whereupon the desired crystalline cholestan-3-one ethylene ketal was obtained in 83% yield, see: Vorbrüggen, H. Steroids 1963, 1, 45. On chromatography of the crude reaction mixture using deactivated alumina, the O-monoacetate of ethylene glycol was isolated alongside the desired ethylene ketal. Because amide acetals, such as 7g, seemed to transform carboxylic acids into their corresponding esters, I reacted compounds such as benzoic and nicotinic acid, as well as phenol and 2,4,6-trichlorophenol, with diethyl acetal 7b and dibenzyl acetal 7c and, indeed, obtained the corresponding esters and phenyl ethers. While wondering about the possible scope of these new esterifications, I contacted Dr. John G. Moffatt at the neighboring Syntex Laboratories in Palo Alto and asked him whether he might be interested in trying to synthesize esters from nucleotides using diethyl acetal 7b. A few days later, John called and told me that a new postdoc of his, who had just completed his Ph.D. with A. Eschenmoser at ETH in Zürich, had informed him that A. Eschenmoser was also working on the esterifications of carboxylic acids with amide acetals. When I discussed this work with C. Djerassi, who had generously supported my little additional research project, he only commented, ‘Write him!’. This I did although with some trepidation as a completely unknown scientist, but I received an immediate reply in which A. Eschenmoser suggested that we should publish our results in two adjacent communications in Angewandte Chemie (see refs. 38 and 39). I later met A. Eschenmoser on a number of occasions and exchanged information with him on various aspects of the field of nucleic acids. I learnt to admire A. Eschenmoser not only for his intellectual brilliance, but also, in particular, as a scientist and colleague, who has always been absolutely fair to other scientists in his publications and lectures by giving credit to whom ever credit was due, which unfortunately is not as common nowadays.
42
Holy A.
Bald RW.
Hong NgD.
Collect. Czech. Chem. Commun.
1971,
36:
2658
43
Feinauer R.
Angew. Chem. Int. Ed. Engl.
1967,
6:
178
44
Thenot JP.
Horning EC.
Anal. Lett.
1972,
5:
519
45
Fitt JJ.
Geschwend HW.
J. Org. Chem.
1977,
42:
2639
46
Taylor EC.
Macor JE.
J. Heterocycl. Chem.
1985,
22:
409
47
Gupton JT.
Miller JF.
Bryant RD.
Maloney PR.
Foster BS.
Tetrahedron
1987,
43:
1747
48
Smodis J.
Zupet R.
Petric A.
Stanovnik B.
Tisler M.
Heterocycles
1990,
30:
393
49
Stanovnik B.
Svete J.
Tisler M.
Zorz L.
Hvala A.
Simonic I.
Heterocycles
1988,
27:
903
50
O’Donnell MJ.
Bruder WA.
Daugherty BW.
Liu D.
Wojciechowski K.
Tetrahedron Lett.
1984,
25:
3651
51
Grubb MF.
Callery PS.
J. Chromatogr.
1989,
469:
191 ; Chem. Abstr. 1989, 111, 208476
52
Böttcher H.
Gericke R.
Liebigs Ann. Chem.
1988,
749
53
Clark RD.
Repke DB.
Heterocycles
1984,
22:
195
54
Widmer U.
Synthesis
1983,
135
55
Mohacsi E.
Leimgruber W.
Baruth H.
J. Med. Chem.
1982,
25:
1264
56
Mohacsi E.
Synth. Commun.
1983,
3:
827
57
Xie J.
Soleilhac J.-M.
Schmidt C.
Peyroux J.
Roques BP.
Fournie-Zaluski M.-C.
J. Med. Chem.
1989,
32:
1497
58
Tilley JW.
Sarabu R.
Wagner R.
Mulkerins K.
J. Org. Chem.
1990,
55:
906
59
Nakane M.
Reid JA.
Han W.-C.
Das J.
Truc VC.
Haslanger MF.
Garber D.
Harris DN.
Hedberg A.
Ogletree ML.
Hall SE.
J. Med. Chem.
1990,
33:
2465
60
Watson NS.
Bell R.
Chan C.
Cox B.
Hutson JL.
Keeling SE.
Kirk BE.
Procopiou PA.
Steeples IP.
Widdowson J.
Bioorg. Med. Chem.
1993,
3:
2541
61
Lester MG.
Giblin GMP.
Inglis GGA.
Procopiou PA.
Ross BC.
Watson NS.
Tetrahedron Lett.
1993,
34:
4357
62
Hamprecht D.
Josten J.
Steglich W.
Tetrahedron
1996,
52:
10883
63
Unangst P.
Connor DT.
Miller SR.
J. Heterocycl. Chem.
1996,
33:
1627
64
Tagat JR.
McCombie SW.
Nazareno DV.
Boyle CD.
Koslowsk i JA.
Chackalamannil S.
Josien H.
Wang Y.
Zhou G.
J. Org. Chem.
2002,
67:
1171
65
Choong IC.
Lew W.
Lee D.
Pham P.
Burdett MT.
Lam JW.
Wiesmann C.
Luong TN.
Fahr B.
DeLano WL.
McDowell RS.
Allen DA.
Erlanson DA.
Gordon EM.
O’Brian T.
J. Med. Chem.
2002,
45:
5005
66
Venkatraman S.
Njoroge FG.
Girijavallabhan V.
McPhail AT.
J. Org. Chem.
2002,
67:
2686
67
Ludwig J.
Lehr M.
Synth. Commun.
2004,
34:
3691
68 Pieraccioli D. inventors; EP 0370974.
; Chem. Abstr. 1990, 113, 191168
69
Armstrong A.
Brackenridge I.
Jackson RFW.
Kirk JA.
Tetrahedron Lett.
1988,
29:
2483
70
Nakajima N.
Horita K.
Abe R.
Yonemitsu O.
Tetrahedron Lett.
1988,
29:
4139
71
Tomooka K.
Kikuchi M.
Igawa K.
Suzuki M.
Keong P.-H.
Nakai T.
Angew. Chem. Int. Ed.
2000,
39:
4502
72
Mathias LJ.
Synthesis
1979,
561
73
Eliel EL.
In Steric Effects in Organic Chemistry
Newman MS.
John Wiley;
New York:
1956.
p.76-77
74
Lythgoe B.
Moran TA.
Nambudiry MEN.
Ruston S.
Tideswell J.
Wright PW.
Tetrahedron Lett.
1975,
16:
3863
75
Vorbrüggen H.
Krolikiewicz K.
Angew. Chem. Int. Ed. Engl.
1977,
16:
876
76
Asaoka M.
Yanagida N.
Takei H.
Tetrahedron Lett.
1980,
21:
4611
77
Shishido K.
Tanaka K.
Fukumoto K.
Kametani T.
Tetrahedron Lett.
1983,
24:
2783
78
Kuroda C.
Nakamura T.
Hirota H.
Enomoto K.
Takahashi T.
Bull. Chem. Soc. Jpn.
1985,
58:
146
79
Shishido K.
Tanaka K.
Fukumoto K.
Kametani T.
Chem. Pharm. Bull.
1983,
33:
532
80
Villemin D.
Synthesis
1987,
154
81
Kuroda C.
Shimizu S.
Satoh JY.
J. Chem. Soc., Chem. Commun.
1987,
286
82
Kuroda C.
Shimizu S.
Satoh JY.
J. Chem. Soc., Perkin Trans. 1
1990,
519
83
Friederich D.
Paquette LA.
J. Org. Chem.
1991,
56:
3831
84
Nishitani K.
Konomi T.
Okada K.
Yamakawa K.
Heterocycles
1994,
37:
679
85
Rüttimann A.
Wick A.
Eschenmoser A.
Helv. Chim. Acta
1975,
58:
1450
86
Vogel E.
Caravatti GM.
Franck P.
Aristoff P.
Moody C.
Becker A.-M.
Felix D.
Eschenmoser A.
Chem. Lett.
1987,
219
87
Mulzer J.
Kühl U.
Brüntrup G.
Tetrahedron Lett.
1978,
19:
2953
88
Mulzer J.
Brüntrup G.
Chem. Ber.
1982,
115:
2057
89
Hara S.
Taguchi H.
Yamamoto H.
Nozaki H.
Tetrahedron Lett.
1975,
16:
1545
90
Koreeda M.
Luengo JI.
J. Org. Chem.
1984,
49:
2079
91
3β-(4-Nitrophenoxy)-5α-androstan-17-one
(82)
To a boiling solution of 3α-hydroxy-5α-androstan-17-one (80) (0.249 g, 1 mmol) in abs benzene (15 mL) was added a third of a suspension of DMF dineopentyl acetal 7d (4.3 mL, 15 mmol) and 4-nitrophenol (81) (2.087 g, 15 mmol) in abs benzene (15 mL). After heating at 80 °C for 24 h, the rest of the suspension was added in small portions over a period of 48 h. The mixture was heated at 80 °C for a further 14 h and then was cooled. Ice (20 g) was added to the mixture, which was then extracted with 2 M NaOH (2 × 35 mL). The extracts were dried (MgSO4) and benzene was evaporated off to give the crude crystalline product (1.618 g), which on recrystallization (MeOH) gave slightly impure 3β-(4-nitrophenoxy)-5α-androstan-17-one (82) (0.188 g). Filtration of the product in CH2Cl2 over a small column of neutral alumina (7.5 g, activity II) and recrystallization of the eluate (MeOH) gave pure 82; mp 214 °C; [α]D
+62.9 (c 1, CHCl3). The combined mother liquors were column chromatographed [silica gel (70 g), cyclohexane]. Elution [cyclohexane-toluene, 2:3 (200 mL), then 3:7 (400 mL)] afforded homogeneous 5α-androst-2-en-17-one, which was recrystallized (pentane) to give the pure side product. Yield: 0.056 g (24%); mp 106.5-107 °C. Further elution (toluene, 1 L) gave additional pure 82 (0.051 g). Combined yield: 0.239 g (68%).
92
Fahrenholtz KE.
Lurie M.
Kierstaead RW.
J. Am. Chem. Soc.
1967,
89:
5934
93
Thenot J.-P.
Horning EC.
Stafford M.
Horning MG.
Anal. Lett.
1972,
5:
217
94
Cohen HL.
J. Polym. Sci., Polym. Chem. Ed.
1976,
14:
7
95 Falkowski L, Stefanska B, Bylek E, Golik J, Zielinski J, and Boroski E. inventors; PL 120035.
; Chem. Abstr. 1984, 101, 38277
96
Midgley G.
Thomas CB.
J. Chem. Soc., Perkin Trans. 2
1984,
1537
97
Hoberg H.
Minato M.
J. Organomet. Chem.
1991,
406:
C25
98
Wong PL.
Moeller KD.
J. Am. Chem. Soc.
1993,
115:
11434
99
Joniak K.
Chem. Pap.
1995,
49:
198
100
Jones BCNM.
Drach JC.
Corbett TH.
Kessel D.
Zemlicka J.
J. Org. Chem.
1995,
60:
6277
101
Mcguire JM.
Powis PJ.
J. Chromatogr. Sci.
1998,
36:
104
102
Sutton PW.
Bradley A.
Elsegood MRJ.
Farras J.
Jackson RFW.
Romea P.
Urpi F.
Vilarrasa J.
Tetrahedron Lett.
1999,
40:
2629
103
Hirsch JA.
Schwartzkopf G.
Synth. Commun.
1974,
4:
215
104
Becker AM.
Irvine RW.
McCormick AS.
Russel RA.
Warrener RN.
Tetrahedron Lett.
1986,
27:
3431
105 Conley RA. inventors; EP 0216469.
; Chem. Abstr. 1987, 107, 115366
106
Ali MS.
Hanson JR.
Ahmad VU.
Z. Naturforsch., B
1997,
52:
1237
107
Bjoerkman S.
J. Chromatogr.
1982,
237:
389
108
Gloede J.
J. Prakt. Chem.
1970,
312:
712
109
Gloede J.
Costisella B.
J. Prakt. Chem.
1971,
313:
277
110
Methyl 4-Nitrobenzoate
(88)
Using 7a and DCE: To a suspension of 4-nitrobenzoic acid (87) (3.342 g, 20 mmol) in DCE (25 mL) was added a solution of DMF dimethyl acetal 7a (8.2 mL, 62 mmol) in DCE (25 mL) over a period of 5 h at 24 °C with stirring. Stirring was continued for a further 66 h, whereupon a clear yellowish solution resulted. After evaporation at 35 °C/0.5 Torr, the crystalline residue was extracted with boiling Et2O (3 × 70 mL) resulting in, after further evaporation, crude methyl 4-nitrobenzoate (88). Yield: 3.265 g (90%); mp 92-94 °C. Recrystallization from boiling hexane resulted in pure 88; mp 95-96 °C (Lit. mp 96 °C; see also ref. 108). The crystalline yellowish residue (0.480 g) that remained after the extraction with Et2O was recrystallized (abs EtOH, 5 mL) to give acidic tetramethylammonium salt 89 (0.063 g); mp 278-281 °C. On acidification of the mother liquor with 1 M H2SO4 and extraction with CH2Cl2, pure 4-nitrobenzoic acid (87) was recovered; mp 242 °C (see also ref. 20).
Using 13a and DCE: To a suspension of 4-nitrobenzoic acid (87) (2.507 g, 15 mmol) in DCE (40 mL) was added N,N-tetramethylene-formamide dimethyl acetal 13a (4.656 mL, 30 mmol) with stirring at 30 °C. After 4 h at 30 °C, the mixture was stirred with sat. NaHCO3 soln (20 mL) and then was extracted with Et2O (3 × 20 mL). After evaporation of the ethereal extract, pure, homogeneous, crystalline methyl 4-nitrobenzoate (88) was obtained. Yield: 2.496 g (92%). The repetition of this experiment over a period of 25 h at 30 °C and workup with NaHCO3 gave crystalline 88; Yield: 2.712 g (100%) (see also ref. 20)
Using 7a and THF: To a stirred boiling solution of 4-nitro-benzoic acid (87) (0.84 g, 5 mmol) in abs THF (30 mL) in a 100-mL three-necked round-bottom flask, connected to a reflux condenser and an addition funnel and in an oil bath at 80 °C, was added dropwise a solution of DMF dimethyl acetal 7a (1.8 mL, 15 mmol) in abs THF (20 mL), where-upon a colorless precipitate formed. After the addition of about 10 mL (7.5 mmol) of the THF solution of 7a, a clear yellowish solution resulted, indicating the completion of the reaction. Evaporation of the mixture afforded the crude crystalline product (1.33 g), which was dissolved in tert-butyl methyl ether (20 mL) and filtered over a layer of silica gel (18 g) to give crystalline methyl 4-nitrobenzoate (88). Yield: 0.94 g (100%); mp 94-96 °C. Recrystallization (boiling hexane, 40 mL) resulted in the first crop of pure 88 (0.69 g); mp 96 °C. Concentration of the mother liquor afforded another crop of pure 88 (0.16 g). Combined yield: 0.85 g (90%). The remaining hexane mother liquor still contained, according to TLC (hexane-EtOAc, 4:1), methyl 4-nitrobenzoate (88).
111
Stork G.
Brizzolara A.
Landesman H.
Szmuskovicz J.
Terrell R.
J. Am. Chem. Soc.
1963,
85:
207
112
Stamhuis EJ.
Maas W.
J. Org. Chem.
1965,
30:
2156
113
Huisgen R.
Feiler LA.
Otto P.
Tetrahedron Lett.
1968,
9:
4485
114
Effenberger F.
Fischer P.
Schoeller WW.
Stohrer WD.
Tetrahedron
1978,
34:
2409
115
Dimethyl Fumarate
(94)
To a stirred boiling solution of fumaric acid (92) (1.16 g, 10 mmol) in abs THF (30 mL) in a 100-mL three-necked round-bottom flask, connected to a reflux condenser and an addition funnel and in an oil bath at 80 °C, was added dropwise a solution of DMF dimethyl acetal 7a (4 mL, 30 mmol) in abs THF (20 mL) over a period of 1 h, whereupon salt 93 formed as a colorless precipitate. Because the solution was still somewhat turbid, additional 7a (1.3 mL, 10 mmol) in abs THF (10 mL) was added over a period of 0.5 h, and the mixture was heated for another 0.5 h and stirred overnight at r.t. for 16 h. The resulting yellowish solution was decanted from a small amount of colorless precipitate (0.03 g), which was washed with tert-butyl methyl ether and the extracts were filtered. On evaporation, the filtrate gave a crude yellowish crystalline substance (1.63 g) that was dissolved in tert-butyl methyl ether (125 mL) and filtered over a layer of silica gel (16 g). The slightly yellowish solution gave, on evaporation, spontaneously crystallizing homogeneous dimethyl fumarate (94). Yield: 1.3 g (93%); mp 99-103 °C; R
f
= 0.35 (hexane-EtOAc, 9:1).
116
Lau CM.
Boyer JH.
J. Chem. Res., Synop.
1990,
34
117
Shvo Y.
Shanan-Atidi H.
J. Am. Chem. Soc.
1969,
91:
6689
118
Wawer I.
Osek J.
J. Chem. Soc., Perkin Trans. 2
1985,
1669
119
(
E
)- and (
Z
)-3-(Dimethylamino)acrylonitrile
(111) and
(112)
In a 100-mL three-necked round-bottom flask, connected to a reflux condenser and an addition funnel and in an oil bath at 80 °C, was stirred a solution of cyanoacetic acid (104) (1.70 g, 20 mmol) in 1,4-dioxane (30 mL, previously dried over 4 Å MS). To this solution was added DMF dimethyl acetal 7a (4 mL, 30 mmol) in 1,4-dioxane (20 mL) with vigorous stirring over a period of 1 h. Heating was continued for a further 1 h. After cooling the mixture and evaporating off the solvent, the crude dark oily product (3.16 g) was extracted with tert-butyl methyl ether and the extracts were filtered over a layer of silica gel (ca. 16 g). On evaporation of the yellow filtrate, homogeneous 3-(dimethylamino)acrylonitrile (111/112) was obtained. Yield: 1.92 g (100%); R
f
= 0.72 (tert-butyl methyl ether).